Saws

The invention and development of the saw followed soon after the discovery of copper in the Near East about four thousand years ago. The early Egyptians used copper hand saws up to 20 inches long, with a pistol-shaped handle lashed to the tang. Cretan carpenters about 1600 BC had large bronze saws for cross cutting and ripping.

The first iron saws were no stronger than the bronze ones they replaced; the only advantage was that the iron was more readily available. Later on, the Greeks and Romans made many important improvements to the iron hand saws, including various types of wooden frames for straining the blade and setting the teeth alternately so that the saw kerf could be cut slightly wider than the thickness of the saw. The cutting edge could then be made straight and the teeth shaped to cut on the push stroke, giving a more accurate and efficient action.

During the Middle Ages, improvements to the tools were confined to the design of the wooden frames and handles and various methods of cutting and setting the teeth.

About the middle of the seventeenth century the development of the process of rolling wide steel strip, mainly at Sheffield in England and in Holland, ushered in significant changes in the design of hand saws. The wider plates thus obtained were strong enough to dispense with wooden frames for straining the blades and the main problem became the shape and method of fixing the handles. The Dutch and Scandinavian sawmakers used a pistol-shaped handle with a ferrule fixed to a tang on the upper part of the blade.

The English makers, however, preferred a handle nearly as wide as the heel of the saw itself, cut from a flat plank about 1 inch thick, with an oval hand hole and angled grip, riveted or screwed to the blade. With further refinements in detail, this became the standard pattern for hand saws of all types almost everywhere. For accurate work on the bench, carpenters, cabinetmakers and the like in the early eighteenth century also used sash, tenon and dovetail saws with fine teeth on a thinner blade, which was strengthened by a steel or brass back. These "backed" saws were also fitted with the new type of handle.

Although the traditional framed saws with narrow blades are still widely used in Europe for all types of bench work, ripping and cross cutting, their use in English-speaking countries is confined to compassed or curved work. These "bow" saws or turning saws have changed very little since medieval times.

Saw teeth

The groove cut in a piece of wood by a saw is called the kerf. To prevent the saw blade continuously jamming in the kerf, the teeth are "set", that is, bent sideways alternately to the right and left, so that they cut a kerf slightly wider than the thickness of the blade.

Saw teeth design

Cross cut saw teeth (left) act as knife points to sever the wood fibers while rip saw teeth (right) work like a chisel.

The design of the saw tooth also depends on the kind of lumber to be cut. For cutting with the grain it is best to use a rip saw, which has teeth filed at 90° across the blade. These act like a series of tiny chisels, cutting along the grain. For cross grain lumber use a cross cut saw with teeth filed at an angle of 65° to 75° across the blade. These act like knife blades to score on each side of the cut.

The size of saw teeth varies enormously. Large teeth with deep spaces or "gullets" in between are best suited to cut softwood. They offer little resistance to the saw and so a lot of sawdust is produced, which is carried clear of the kerf by the large gullets. Hardwoods, on the other hand, are more difficult to cut and therefore require more and smaller teeth per inch. The nature of the work also determines the size of the tooth. Coarse ripping can be done with large teeth while fine joint cutting requires small, finely set teeth.

Teeth are specified in points per inch. This measurement includes the teeth at each end, therefore a measurement of 8 points per inch would actually mean 7 teeth within that inch. Fine bow saws are measured in teeth per inch.

Sharpening a saw

There are several stages to sharpening a saw depending on its condition. Through persistent misuse a saw may have hollows worn in the row of teeth or it may have been badly sharpened to produce uneven sized teeth. In either case it will require leveling to begin the process of bringing it back to its original condition.

A file mounted in hardwood should be used to level the teeth along the entire length of the saw. The wood acts as a jig, running against the face of the saw blade to keep the file square and flat on the teeth.

Shaping the teeth

The teeth must now be shaped with a saw file to regulate the size and shape. The object is to maintain an even "pitch" to each tooth. Pitch is the angle at which the front of the tooth leans toward the toe of the saw. Try to keep to the original pitch of the saw, which may be up to 14 for a cross cut saw, moving back to upright for rip saw.

Mounting the file

Mount the smooth file in a block of hardwood.

Positioning the saw

Hold the saw, teeth uppermost, between two softwood lengths and clamp it in a vise.

The angle between each tooth of any saw is a constant 60°. Lower the saw between two strips in the vise as near as possible to the teeth. Choose a saw file which is just over twice the depth of the tooth. Place the file in the first gullet, holding it horizontally and at right angles to the blade. Maintain the correct pitch while holding the file in one hand and the tip between thumb and finger of the other. File with even forward strokes. File each gullet in turn until all the fiats are removed and the teeth are uniform in shape. Any burrs produced on one side of the blade can be removed by a light dressing with an oilstone.

A file which is twice the depth of the teeth will maintain its accuracy for longer.

Saw file position

Hold the file at an approximate angle of 70° to the blade.

Setting the teeth

The teeth must now be set to produce the correct width of kerf. The easiest method is to use a saw set (see below) swhich automatically bends each alternate tooth exactly the right amount and to the correct depth. Adjust the saw set to correspond with the points per inch of the saw. Starting at one end of the saw, position the saw set over alternate teeth, lining them up with the plunger, and squeeze the handles to press the teeth against the anvil. Reverse the saw and repeat the sequence on the intermediate teeth. Before final sharpening, make sure the set is even. To do this, hold the saw horizontally at eye level and against the light. Any unevenness will show up clearly and the set can be adjusted.

Only the top half of the tooth is bent when setting.

Checking set

By holding the saw horizontally at eye level, the correcthess of the set can be easily confirmed.

Final sharpening

To complete the operation the front edge of each tooth must be filed to the correct angle. With the saw still held in the vise, position the saw handle to your right. Place the file on the front edge of the first tooth set toward you. Keeping the file horizontal, give the tooth two or three firm yet steady strokes. Move the file along the blade filing each alternate tooth in the same way. Reverse the saw and file the intermediate teeth.

Rip saw teeth

Rip saw teeth are filed at right angles across the saw blade.

Cross cut teeth

Cross cut teeth are sharpened in the same way. The back edge of each tooth will be filed automatically as you file the front edge of the tooth from behind. When the saw is reversed make sure that the handle of the file is angled away from the saw handle again when filing the intermediate teeth.

Hardened teeth on some modern saws cannot be file sharpened; they must be maintained by the supplier.

Cross cut teeth are filed at 70° across the blade.

Hold the file at an approximate angle of 70° to the blade.

Saw Set

SIZE: To set saws from 4 to 16 points per in.

MATERIAL: Cast metal, reinforced nylon

USE: To set saw teeth to the correct angle

The saw set is designed to bend the teeth of a saw to exactly the right angle to produce the required cut or kerf. When the handles are squeezed together a plunger presses the tooth against an anvil (a wheel with a graduated angle on the face) which corresponds to the correct setting for saws with teeth from 4 to 16 points per inch. Saws that measure more than 16 points per inch should be reset by a saw repair specialist.

The plunger presses the saw teeth against the anvil to produce-the required "set".

Adjusting the saw set

Squeeze the handles to hold anvil firmly; undo locking screw. Release handles and adjust anvil until relevant point number engraved in top edge lines up with plunger. Squeeze the handles again and tighten the locking screw. Set the teeth of the saw as detailed above.

Move the saw set along the blade locating it over alternate teeth. Reverse the saw and set the remaining teeth.

Two-Man Cross Cut Saw

SIZE: 4 to 7ft.

MATERIAL: Blade: steel; Handle: hardwood

USE: To fell trees and cut logs

The two handed cross cut saw is one of the oldest style of saws surviving in modern catalogs. It consists of a long flat blade with cutting teeth on the underside and an upright handle at each end. The shape of the blade seems to have been originally determined by local tradition and does not affect the cut in any obvious way. The shape of the teeth on the other hand, is very important.

The simplest cross cut design, known as the "peg" tooth, is an evenly spaced row of V-shaped teeth. Each tooth is filed on both edges so that it cuts in both directions. Another shape has a deep gullet between each tooth. While the teeth do the cutting, the sawdust is carried out of the cut in the gullets. This prevents the saw jamming in the cut and is especially important for cutting unseasoned wood.

The other design for cross cut saws has rows of cutting teeth interspersed by unsharp-ened "raker" teeth, designed to rake the sawdust clear of the kerf. The "lance" tooth saw has a group of 4 cutting teeth and a pair of rakers separated by deep gullets.

Felling trees

Felling large trees is a skilled operation and should not be attempted by an amateur without expert help and advice. The following is a description of the way a two-man cross cut saw is used in tree felling and should not be regarded as complete instructions.

The tree is "undercut" on the side facing the direction in which it is to fall. Above this cut a notch, angled to 45°, is chopped out with an axe. The cross cut is used once more to make the "backcut", another horizontal cut in the opposite side of the tree approximately 2in. above the bottom of the notch, stopping within 2in. of the notch. The wood between the cuts acts as a hinge for the falling tree. At this stage, the tree will usually fall under its own weight, and experienced workmen will stand aside, one of them removing the saw. If it does not fall naturally, drive wedges into the backcut.

Cutting down the tree

Make the undercut 12in.from the ground. Above the cut, chop out the angled notch with an axe. Make the backcut. Let the tree fail or encourage it with wedges.

One-Man Cross Cut Saw

SIZE: 2-1/2 to 5ft.

MATERIAL: Blade: steel; Handle: hardwood

USE: To fell trees and to cut logs to length

One-man cross cut saws have a hand saw style handle and a supplementary upright handle, which can be fitted anywhere along the upper edge of the blade as a secondary hand grip. It is normally positioned immediately in front of the main handle but can be fitted at the toe of the blade to convert the tool into a two-man saw.

One-man cross cut blades normally retain their full depth for most of their length, tapering rather abruptly at the toe. All the styles of teeth described for two-man saws are available for the one-man, but whatever the design there is usually a short length of peg teeth to correspond with the taper.

Cutting logs to length

Cutting logs to length is not as dangerous as felling trees, and can be tackled by an amateur. Prevent the log from rolling by wedging it on both sides. You may have to drive wedges into the kerf as the cut progresses to prevent the saw jamming.

Chain Saw

OTHER NAME: Buzz saw

SIZE: Bar length: 10 to 20in.; Power: electric: 1100 to 1200 watts: gasoline engine: 3-1/2 to 5-1/2hp

MATERIAL: Various

USE: To fell trees and cut logs to length

A modern chain saw cuts fast and efficiently even through unseasoned timber. A gasoline engine or electric motor drives a continuous toothed chain which is supported and guided by a metal blade which is known as the guide bar.

Safety features are incorporated to prevent accidental starting of the tool. Electric saws are fitted with a "lock-off" button and engine driven saws have a centrifugal clutch, which disengages when the engine is idling.

Felling with a chain saw

Felling large trees with a chain saw is just as hazardous as using a two-man cross cut saw, and the operation should only be undertaken with expert supervision. The chain saw makes undercutting very simple as it can be used to make both the initial horizontal cut and the angled notch. This dispenses with the axe needed to make the notch when felling with a two-man cross cut.

For a normal felling cut, start the backcut 2in. above and 2in. behind one end of the notch and swing the bar into the tree keeping it parallel to the bottom of the undercut. Be careful not to cut through the tree hinge.

To cut through a tree which is wider than the length of the guide bar, make successive cuts around the tree making sure that each cut is in the same plane as the previous one.

Normal felling cuts

Swing the bar into the tree keeping it parallel to the bottom of the undercut.

Wider felling cuts

Make successive cuts around the tree keeping them in the same plane.

Folding Saw

OTHER NAMES: Flexible saw, chain saw

SIZE: 4ft.

MATERIAL: Steel

USE: To cut off branches

The folding saw is a length of flexible, toothed steel with a loop at either end.

A rope is attached by the loop to each end so that the saw can be pulled in both directions. One end of the rope is thrown over the branch and the folding saw hauled up. One person takes either end of the rope and, standing well clear of the branch, they pull in alternate directions until the branch is severed.

It is dangerous to cut a branch from below unaided, as both the branch and the saw itself could fall.

Log Saw

OTHER NAME: Bow saw

SIZE: 24 to 36in.

MATERIAL: Blade: steel; Frame: tubular steel

USE: To cut logs to length and prune trees

The blade is held under tension in a tubular steel frame. In modern versions tension is applied by a quick-release lever. The lever combined with an oval sectioned frame provides a comfortable hand grip. The blades, which are replaceable, are made up of pegged teeth or a combination of pegged teeth and gullets to provide cutting action in both directions.

Hand Saw

OTHER NAMES: Rip saw, cross cut saw, panel saw

SIZE: Rip saw: Length: 26in.; Points: 5 per in.; Cross cut: Length: 24 to 26in.; Points: 6 to 8 per in.; Panel; Length: 20 to 22in.; Points: 30 per in.

MATERIAL: Blade: steel; Handle: beech, plastic

USE: To cut large planks or panels

Hand saws as a group have long, tapering, unsupported blades fitted with a closed handle. Although they vary in length, the main difference lies in the number and shape of the cutting teeth (see above). The shape of the blade varies with the quality of the saw. A lot of modern saws, and some more cheaply produced traditional style saws, have a straight back and a blade of uniform thickness throughout.

The better traditional saw has a pronounced dipping curved back, known as a "skew" back. This is to reduce die weight at the toe thus improving the balance of the tool. They are also "taper ground", that is, ground on both sides of the blade to taper from the handle to the toe on the back of the saw while remaining a constant thickness just above the teeth. This improves the clearance of the saw in the kerf, even with a minimum set, which makes the saw easier to drive and wastes less wood.

The traditional hand saw handle is cut from a close grain hardwood, usually beech. In some ways it is a curious design, for it is impossible to cut a handle from solid wood without leaving short grain somewhere, and it is puzzling that the cross grain strength of piy-wood was never used for saw handles. Modern saws are often fitted with moulded plastic handles of a less elaborate design. In either case a well-designed handle should be set low on the back of the blade for correct balance and it should be angled to produce maximum thrust approximately halfway along the cutting edge.

RIP SAWS

The rip saw with its chisel-like teeth is designed specifically for cutting lumber along it's length, that is, with the grain.

Using the rip saw

When cutting wood it is important for the board to be supported on saw horses. Make sure the board is high enough to prevent the toe of the saw from striking the ground and low enough to get your shoulder above the job. Rest one knee on the board to hold it in place and position the saw on the waste side of the marked line. Your saw arm should be free to move alongside your body, the forearm in line with the blade. Grip the handle naturally but extend the forefinger in line with the blade to prevent the tool twisting in the hand and making the cut wander off line.

Hold the saw at approximately 45° to the work and guide the blade with the thumb of the left hand until the cut is well-established. Make short backward strokes until the cut is under way and then take full strokes using almost the full length of the blade. A reasonably slow, even stroke will be far less tiring and if the saw is sharp and correctly set it will quickly cut through the board. Sometimes stress builds up in lumber during the drying process, so that as you cut into the board, stress is released and the wood begins to move. This may close on the blade of the saw. To keep the cut open drive small hardwood wedges into it behind the saw blade.

Sawing at the board's end

As you approach the board's end it is often easier to finish the cut by reversing the board and making a second cut to meet the first.

Holding the saw

Hold the saw at approximately 45° to the work. Use the thumb of the left hand as a guide.

Positioning the board

Rest your knee on the board to hold it on the saw horses.

Finishing the cut

It is often easier to reverse the board and make a second cut to meet the first.

CROSS CUT AND PANEL SAWS

Cross cut saws are designed to cut lumber across the grain. The teeth are filed so that they score two lines and remove the waste between. The panel saw is a smaller version of the cross cut and is particularly useful for cutting panels of hard-board, plywood and particle board to size.

Using a cross cut saw

When using a cross cut saw, support the wood on saw horses as before, but stand to the inside with one knee resting on the work. Make sure that your own weight does not close up the cut, jamming the saw. Start and proceed with the cut as for a rip saw.

Ending the cut

Support the waste with the oihei hand and make slow careful strokes to prevent the waste breaking off..

Supporting a panel

Support a springy panel on either side of the cut; large panels can be supported by planks across the saw horses.

Back Saw

OTHER NAMES: Tenon saw, dovetail saw

SIZE: Length: 8 to 14in.; Points: 11 to 20 per in.

MATERIAL: Blade: steel;  Handle: beech, plastic

USE: To cut joints

Back saws have a straight blade, parallel top and bottom, with a heavy strip of steel or brass wrapped along the back to provide rigidity.

The handles are similar in shape to those on hand saws except that they are generally mounted higher. Smaller back saws are often fitted with an open handle. They are known as dovetail saws in Britain.

Back saws typically have cross cut teeth for general bench work, such as cutting smaller sections of lumber to length. Smaller back saws, used to cut dovetails by working mainly in line with the grain, are sharpened with fine rip saw type teeth.

When starting the cut, back saws are presented to the work at an angle in a way similar to that described for cross cut and rip saws. Once the cut is established, these saws are used more square to the work than hand saws are.

Cutting a tenon

A tenon is cut entirely with a back saw, its size depending on the nature of the work.

1. Hold the wood in a vise angled away from you and saw from one corner down to the shoulder line. Reverse the work and saw the opposite corner down to the other shoulder line.

2. Stand the work upright in the vise and join the two cuts, finishing parallel with the marked shoulder line.

3. To cut shoulder line place work on a bench hook. Keep blade parallel to tenon; do not cut into it at one end before the waste is removed.

Dovetail Saw

OTHER NAME: Gent's saw

SIZE: Length: 4 to 10in.; Points: 15 to 21 per in.

MATERIAL: Blade: steel; Handle: beechwood

USE: To cut very fine joints

The dovetail saw is a small back saw with a straight chisel-type handle. The small teeth are finely set to cut a very narrow kerf required for fine joints. The term "gent's" saw refers to the smaller, delicate tools given to "gentlemen" of an earlier date who enjoyed woodworking as a hobby.

Saws with very fine teeth and narrow blades are called "bead" and "jeweler's" saws.

Veneer Saw

SIZE: Blade length: 3in.

MATERIAL: Blade: steel; Handle: hardwood

USE: To cut thick veneers

The veneer saw has two curved serrated edges. One set of teeth is sharpened for cross cutting, the other for cutting veneers with the grain.

Pruning Saw

SIZE: 12 to 20in.

MATERIAL: Blade: steei; Handle: hardwood

USE: To prune trees

The simplest form of pruning saw, a descendant of one of the earliest forms of saw, is known in modern catalogs as the "Grecian" pattern. The curved, knife-like blade is serrated on the underside with regular teeth facing backward which cut on the pull stroke. The curve of the blade automatically progresses the cut.

The folding pruning saw has a handle the same length as or a little longer than the blade which folds into the handle for storage and safety.

A double edged pruning saw is also available. It normally has fine peg teeth on one side of the blade and a coarser peg tooth and gullet combination on the other side.

Flooring Saw

SIZE: Length: 121 in.; Points: 8 per in.

MATERIAL: Blade: steel;

Handle: beechwood

USE: To cut through floor boards

A flooring saw makes it easy to lift floor boards to check plumbing or electrical wiring. The saw has a curving blade with teeth on the underside and an angled section. The curved blade of the flooring saw lets you cut into a board without having to start with a drill or keyhole saw, and the curved cutting edge is less likely to damage boards either side. The teeth on the back edge enable you to cut up to a baseboard while keeping the handle clear of the wall.

Using the saw

Pry up one end of the board and wedge it open with a piece of scrap wood. Cut across the board at or near the joist.

Portable Circular Saw

OTHER NAMES: Cut-off saw, utility saw, builder's saw, electric hand saw

SIZE: Unloaded blade speed: 3,000 to 5,500rpm; Weight: 1\ to 14lb

MATERIAL: Various

ACCESSORIES: Saw blades, guide fence, saw bench

USE: To cut solid lumber and board to size

The portable circular saw is an invaluable power tool. It is primarily a woodworking tool, but with special blades fitted, it can cut a number of materials with equal ease. Saws are manufactured as a purpose made tool or as an attachment to a power drill; the latter may be underpowered for some jobs, but it is much cheaper. Larger industrial saws are available, but a saw which takes a 5in. or l^in. diameter blade is normally sufficient.

All portable circular saws should be fitted with a fixed upper blade guard and a lower blade guard which is pushed back as the saw passes through the work. The lower guard is spring-loaded to return automatically as the blade clears the work. Check that the guard is working efficiently before using the saw and never fix it in an open position when the saw is running. Choose the right blade for the job and disconnect the saw before fitting it.

Drill attachment

This is a cheaper though occasionally underpowered alternative to the circular saw.

SAW BLADES

Blades are specially designed to cut lumber efficiently as well as a variety of other materials. Choose the right blade for the job. An unsuitable blade can ruin the work, wear the blade or strain the motor. Keep the blades sharp for quick clean cutting. Circular saw blades are best sharpened by a professional.

RIP BLADE

Used for cutting lumber parallel with the grain.

CROSS CUT BLADE

This is designed to cut across the grain of solid lumber.

COMBINATION BLADE

This is suitable for cutting lunger in any direction, and for composite boards.

CARBIDE TIPPED BLADE

These hardened tipped teeth stay sharp longer, especially when cutting particle boards.

ABRASIVE DISK

Abrasive disks are flexible and shatterproof. A silicon carbide disk will cut marble, slate and building blocks. An aluminum oxide disk cuts thin gauge ferrous pipes, such as drain pipes and guttering.

METAL CUTTING BLADE

Suitable for aluminum, copper, lead and brass.

PLANER BLADE

Produces a fine finish on all lumber and boards.

FLOORING BLADE

Should be used on secondhand lumber, especially where there is the danger of cutting through nails. Also useful for high glue content materials, such as particle board.

FRICTION BLADE

These blades are for cutting through corrugated iron and thin sheet metal.

Changing a blade

Make sure that the saw is disconnected from the power supply. Check maker's instructions carefully for particular information regarding removal.

Rest the sole plate on the front of the bench with the teeth against the edge. Pull back the lower blade guard and fit a wrench on the blade bolt. Tap the wrench sharply with a mallet to free the bolt and unscrew it by hand. Remove the washer and blade. Looking at the machine from the blade side, the saw blade revolves in a counter clockwise direction; most blades will have an arrow printed on one side to show the direction of rotation. This should be facing you when the blade is fitted. Pass the blade through the slot in the sole plate and replace the bolt and washer to secure the blade to the motor drive shaft. Tighten the bolt with a wrench.

Removing the bolt

Tap wrench with mallet to loosen bolt. Unscrew by hand.

Fitting the blade

With the directional arrow facing you, pass the blade through the slot in the sole plate.

Setting the depth of cut

To cut right through the material with minimum splintering, the blade should be adjusted to project gin. from the underside (a). Place the sole plate on the workpiece with the guard in the open position and the blade against the side edge. Release the depth adjustment knob and swing the body of the saw up, or down, keeping the sole plate flat on the work until the blade is at the required depth. Tighten the knob.

To set the blade to cut partially through the material mark the depth of cut on the edge of the work. Position the blade so that at the lowest point of its arc, the point of a tooth just touches the line (b).

Setting for an angled cut

The sole plate can be adjusted to tilt the saw blade to any angle up to 45'. The bracket fitted to the sole plate is marked with a protractor scale to indicate the desired angle and can be locked in place by the angle adjustment knob. Try the cut on a piece of waste wood to check the accuracy of the angle with a sliding bevel.

Free-hand rip cuts

The saw can be used free-hand to make a rip cut by following a marked line. When positioning this line remember to allow for the thickness of the kerf, which may differ for different blades. Rest the front of the sole plate on the lumber so that the blade just clears the edge. Check position as shown, right. Switch on the saw and wait for it to reach top speed before starting the cut. Advance the saw through the work with a steady pressure, neither so fast that it strains the motor nor so slow that the blade overheats. The sound of the saw is your best guide. Keep your eye on the cutting guide to make sure that tfee-cut does not wander. If the saw jams, or the motor is straining, back off a little to allow the saw to run up to speed again before continuing.

Using a fence guide

A rip fence acts as a guide for making repeated rip cuts quickly and accurately without marking out the work. The fence, which is adjustable, can be fitted to either side of the saw. Set the fence for the width of the cut by measuring from the inside of the fence to the blade. Allow for the set of the blade and position it.

Align free-hand cutting guide, usually marked on the sole plate, with the cutting line.

Make the cut as described for free-hand ripping keeping the fence hard against the edge of the work.

When the blade is set at an angle, the depth of the cut is decreased and should be reset.

Using a guide strip

Clamp a strip to the work parallel to the cut line. Run the edge of the sole against the strip.

Making a cross cut

For an accurate cross cut, you need a guide against which the sole plate of the saw can run, Screw two wood strips together in the form of a "T" square. One strip rests against the far side of the work, while the other lies across the work to form an accurate right angle. Position the "T" square as shown. Run the saw through the work keeping the sole plate pressed against the leg of the "T" square. If the top piece of the "T" is left over length, the saw will cut through it as the cut is finished leaving the remaining piece the exact distance from the blade to the "T" square leg. On subsequent cuts, align the cut end of the "T" head with the cutting line marked on the work to automatically position the leg in the right place.

Positioning the "T" square

From the cut line, measure the distance from the blade to the edge of the sole plate and clamp the "T" square on this line.

Making a mitre cut

Clamp a guide strip to the work at the required angle for accurate results.

Cutting boards to the same length

To cut several boards to the same length, screw a softwood strip to the bench and butt the squared ends of the boards against it. Clamp another wood strip across all the boards to act as a guide for the saw. Cut all the ends of the boards at once in one pass.

Cutting panels

Before a large panel is cut, support it securely on saw horses with wood strips on each side of the cut. Place the board face side downv^vd to achieve the cleanest cut on that side. Clamp a guide strip parallel with the required cutting line and operate the saw in the normal way. On a long saw cut the kerf may close up, pinching the blade. Stop the motor and place a small wedge in the cut behind the saw before continuing.

Cutting a groove

To cut a groove or dado with a circular saw set the blade to the required depth and the guide fence to make a cut for each edge of the groove. Reset the guide to make intermediate cuts and clear out the waste with a wood chisel.

Extending the fence

Screw a hardwood strip to the bench to provide better control and protect the work edge.

Safety factors

Support the work securely and make sure that the blade will not cut anything underneath the work. Do not force the cut or twist the blade. Take up a steady stance and where possible stand to one side of the cutting line. Keep the cord away from the blade and check it regularly for condition. Do not put the saw down while it is still running and never adjust the saw while it is connected to a power supply.

Saw Bench Attachment

SIZE: Table size: 14-1/2 x 10 to 20 x 16in.

MATERIAL: Steel

ACCESSORIES: Portable circular saw

USE: To convert a portable saw to a table saw

Special purpose bench saws are much more powerful and accurate machines incorporating the same features as the attachment.

Some manufacturers supply a saw bench attachment, designed to convert their portable circular saw into a saw table. These are small, lightweight tables and normally will not take other makes of saw. If you are thinking of using this attachment it may influence your choice of saw.

The saw is fitted upside down to the underside of the table with the blade and guard protruding above the surface. It must be fixed securely and accurately aligned with the bench guides. The saw bench has four legs, which must be securely bolted to a work bench. Alternatively it could be fixed to a composite board base, which could be clamped to a bench when required. This has the advantage of" portability and clears the work surface when the saw bench is not required. The angle and depth of the blade is adjusted by the portable saw controls.

Rip sawing

The saw bench is ideal for ripping boards to width, as it leaves both hands free to guide the work. Raise the saw blade to just clear the thickness of the material to be sawn. Set the rip fence the required distance f: om the blade.

Run the saw until it is up to speed before feeding the work against the blade. Holding the work firmly against the fence push it steadily over the blade. Keep both hands well clear of the blade. Do not lean on the work as your own weight may force the cut *o close and jam the saw.

Finishing the cut

To finish the cut, use a push stick, a length of softwood with a notch cut in one end, to feed the work over the blade.

Cross cutting

To cut the ends of rails square, set the mitre fence at right angles to the saw blade. Mark the cut on the front edge of the rail and align it carefully with the blade before switching on. Hold the rail against the fence and slide it in its groove to push the work into the saw.

The ends of the rails can be cut to any angle by setting the mitre fence accordingly and proceeding as for a normal cross cut.

Cutting rail ends

Use both hands for large off cuts and one hand for dealing with smaller wood lengths.

Cutting a rabbet

A rabbet can be cut by using the rip fence with the blade set to cut the depth of the rabbet. Cut one face of the rabbet, reset the saw and cut the other face, removing the waste at the same time.

Cutting a dado

Set the rip fence to make one cut on each side of the groove and make the intermediate cuts to remove the waste. Beveled or "wobble" washers can be fitted to the blade to increase the kerf width considerably when removing the waste. Beveled washers set the blade at an angle so that as it revolves the teeth move from one side to the other.

Cutting a tenon

Cut an accurate tenon joint using the mitre fence set at 90 to the blade. Set the saw to match the depth of the shoulder, Make sure the depth is accurately matched, as otherwise the tenon may weaken. You can cut the length of the tenon with a cross cut hand saw, then cut the shoulder line with the saw bench for accuracy. Turn the work over and repeat the sequence. Mount the blade with a beveled washer to remove the waste quickly and easily.

Make the first cut along the shoulder line and on the waste side. Make further cuts on the waste side one blade width at a time until the joint is complete.

Frame Saw

OTHER NAMES: Bow saw, sweep saw, turning saw

SIZE: Let^th: 8 to 28in.; Width 4 to 3iin.

MATERIAL: Blade: steel; Frame: beechwood

USE: To rip, cross cut and cut curves in lumber

The modern frame saw is based on centuries-old construction. A relatively narrow blade is held in tension by the side pieces or "cheeks" of the frame, pivoting about their centres on the ends of a stretcher rail. The top ends of the cheeks are pulled toward each other either by a twisted cord and toggle stick, or by a threaded rod or a cable, ten-sioned by wing nuts. The stretcher rail and cheeks are either joined by a dry stub mortise and tenon or a bridle joint.

The traditional two-handed method of holding the frame saw controls the direction of the blade and supports the frame. Grip the handle with one hand, the index finger extended in the direction of the blade. Take the blade fixing between the index and second finger of the other hand, wrap the thumb around the cheek and clasp the other fingers around the other hand.

On some European models the blades are fixed in a vertical position for cross cutting, but with a swivel blade for ripping. The British type of frame saw, the bow saw, has a smaller frame and is used for curves.

Holding the frame saw

Hold the saw in both hands for more precise control.

Using the swivel blade

Swing the frame aside to clear long boards when rip sawing.

Coping Saw

SIZE: Length: 6-3/8in.; Bow depth: 4-3/4 and 6-3/4in.

MATERIAL: Blade-frame: steel; Handle: hardwood

USE: To make curved cuts in wood or plastic

The blade of the coping saw is very narrow and has fine teeth grouped at 14 per in. It is held under tension by the spring of the frame. It can be angled to cut in any direction, by twisting the pins extending from the blade holders.

Fitting a blade

Replace a blade when it becomes blunt or is broken. Slacken the saw by turning the handle counter clockwise while restraining the blade holder. Place one end of the blade in the slot in the front blade holder, then insert the other end as shown below.

Tension the frame by turning the handle clockwise. To straighten the blade, line it up with the holder pins.

Securing the blade

Make sure the cross pin of the blade locates behind the front blade holder.

Press the frame against a firm surface until you' can attach the free end in the rear blade holder.

Using the coping saw

Fit the blade with the teeth facing forward for thicker stock. For thin material, set the teeth to face backward and cut by holding the work flat on a bench as for a fret saw. Turn the blade when necessary to clear the work. This is particularly useful when cutting shapes in a panel. First drill a hole in one edge of the shape. Pass the blade through on its own, then connect it to each end of the frame.

Cutting shapes

Clamp the work to the hench and cut the desired shape, angling the blades as necessary.

Fret Saw

OTHER NAMES: Scroll saw, deep throat coping saw

SIZE: Length: 5in.; Bow depth: 11-1/2in.

MATERIAL: Blade, frame: steel; Handle: hardwood

USE: To cut tight curves in wood and plastic

The fret saw is used to work thin sheet materials. It is very similar to the coping saw, but has a much deeper bow to the frame and can, therefore, be used to cut shapes well inboard from the edge of a panel. The blade is so fine, up to 32 teeth per in., that it can cut curves without being angled.

The blade is held at each end by a simple, thumb screw operated clamp. It is fitted like the blade of a coping saw, but the operation is much simpler as the spring of the frame itself is sufficient to tension the blade without further help.

To use the saw, hold the work flat on a bench overhanging the edge. With the saw teeth set to face the handle, saw from below using a pull stroke. The bench backs up the work as it is cut.

Piercing Saw

OTHER NAMES: Lightweight fret saw, jeweler's piercing saw

SIZE: Length: 5 to 6in.; Bow depth: 2-3/4 and 3-3/8in.

MATERIAL: Blade'.frame: steel; Handle: hardwood

USE: To cut tight curves in thin sheet metal

The piercing saw is constructed in exactly the same way as a fret saw, but its extremely fine blade, up to 80 teeth per in., is specifically designed for cutting thin sheet metals, such as steel, copper, brass and aluminum. Jewelers and silversmiths use the saw to cut gold and silver sheet.

The blade is fitted and used as for a fret saw. Some frames adjust to take blades of different lengths, which is a useful and economic way to re-use broken but otherwise functioning blades.

Powered Jig Saw

OTHER NAME: Saber Saw

SIZE: Unloaded speed: 2,700 to 3,300 strokes per minute; Weight:

3| to 61b

MATERIAL: Various

ACCESSORIES: Saw blade, guide fence

USE: To cut curves in various materials

The saber saw, which is designed as a power drill attachment as well as a special purpose saw, is a useful tool in the home workshop. It does not have the power and accuracy of larger saws for cutting large panels or thick sections of lumber, but its versatility is a great advantage. It can not only perform a variety of cuts but, fitted with the appropriate blades, can also saw a large selection of materials.

There are extra long coarse blades for cutting large sections of lumber; shorter blades with different grades of teeth for finer cutting of softwoods, hardwoods and composite boards; hack saw-like blades for cutting metal; and special blades for cutting plastics, masonry, plasterboard, leather, rubber and cardboard. A superior blade is available with carbide tipped teeth and there are also blades edged with tungsten carbide chips of different grades. They cut slower than many blades and are a little more expensive, but last longer and produce a very clean cut with virtually no splintering. They will also tackle ceramics.

Blades should be fitted according to the maker's instructions. Make sure they are securely held and aligned as accurately as possible. Not all manufacturers produce the same range of blades, but some makes are interchangeable. Check that the fitting is identical by comparing a blade from your own machine with any prospective purchase.

Using the saw

The saw is operated by squeezing the trigger. It switches off as soon as the trigger is released. Most models have a lock button which can be pressed to run the saw continuously. The button can be automatically released by squeezing the trigger again. Some types of saw have variable speeds. Use a slow speed for hard materials and a faster speed for soft materials.

Rest the front of the shoe on the work, with the blade just clear of the edge. Advance the saw through the cut keeping the sole on the work and providing just enough forward pressure to cut easily. Forcing the pace will blunt the blade, if not break it. If the cut is too slow, either the blade is blunt, or it is not the right type for the job. When the cut is complete switch off and hold the saw until the blade stops running.

Making a straight cut

Hold work tirmly on a safe surface which allows enough clearance beneath the cut for the blade to work unimpeded. As the saw cuts on the upstroke, any splintering is likely to occur on the top surface so lay the finished face of the material downward. The saw can be used free hand following a marked line.

Some saws have a rip fence accessory to fix to the shoe. The fence runs on the edge of the work to guide the blade in a line parallel to the edge. The saber saw does not do this job as well as a circular saw: the blade must be perfectly lined up with the fence to cut a straight line without being distorted, and on most models this is difficult to achieve. A guide strip can be clamped to the work to prevent the saw wandering off line.

Angled cuts

The sole on many saws can be adjusted to swing the blade over to angles up to 45",

Cutting holes in a panel

To cut an opening in the face of a board, mark and then drill a hole fin. in diameter next to the marked line on the waste side. Insert the blade of the saber saw and follow the line. Cut a circular hole in one operation.

Cut a square hole as shown right. Cut each corner until the waste drops out. Saw in the other direction to remove the remaining waste.

Plunge cutting

Cuts can be made inboard of a panel without drilling a starting hole. This method is known as "plunge" cutting, and needs practice to stop the saw jumping as the blade attempts to enter the work and to prevent the shoe slipping.

Tip the saw forward on the front edge of the shoe with the blade above the surface of the work. Switch on and pivot the saw about the front edge of the shoe until the blade begins to cut. Do not make a forward cut until the shoe is resting firmly on the work.

Starting the cut

Rest the front of the shoe on the work, line up the blade with the marked line and switch on.

Using a square as a guide

Run the sole of the saw against a square held across the work for an accurate square crosscut.

Cutting a square hole

Run the blade into a corner, back off lin. and cut a tight curve to the next side.

Saw position for plunge cutting.

Curved cuts

Most saber saw blades are narrow enough to cut tight curves. Follow the line by eye, cutting on the waste side. Do not force the blade to cut a curve which is straining it. Either change to a narrower blade or remove some of the waste with straight cuts to give greater clearance for the blade.

Make preparatory straight cuts to either a concave (above) or convex (below) curve.

Cutting Metal

The saber saw fitted with the appropriate blade will cut any metal which is normally worked by a hack saw. Back up thin sheet metal with a sheet of composite board, both being cut together to give a clean finish and avoid distorting the metal. Spread a thin film of oil along the cut line and proceed at a steady pace.

Cutting plastic laminates

Saw sheet laminate as for thin sheet metal, keeping it held down firmly onto the backing board. Lay the laminate face downward to avoid chipping on the face side. Always use the blade recommended for fine metal work.

Safety factors

Unplug the saber saw before inserting a bNde and make sure that the "lock-on" button is not operative before plugging the saw in. Keep the cord away from the blade and take particular care that it does not pass under the work where it may be severed by the blade.

Hack Saw

SIZE: To take 8, 10, 12in. blades

MATERIAL: Frame, blade: steel; Handle: zinc, alloy, hardwood

USE: To cut metal

Hack saws are used to cut most metals. The bow frame is adjustable to take different lengths of blade, and may be fitted with a pistol grip handle or a straight hardwood grip. The pistol grip is much more comfortable to use and is less likely to fvist in your hand.

Using a hack saw

Secure the work firmly in a vise. Use your thumb to guide the blade when making short backward strokes to establish the cut, then use the hand to steady the frame. Proceed with full length strokes, establishing a steady rhythm.

Use the hand to steady the frame. Cut on the forward stroke and release pressure on the return stroke.

Cutting thick sections

Saw on all sides working toward the centre to keep the cut square. Mark the metal all around and proceed with the cut using a light oil as a lubricant. Cut away the metal in the centre using the previous cuts as a guide.

Saw to the depth of the blade, rotate the work away from you and continue all around until the cut is established.

Round stock

Hack saws will cut round stock and sheet metal if you adapt the sawing technique. Sandwich sheet metal between plywood.

Rotate metal tube away from you during the cut to prevent the blade snatching and to keep the guide line in view.

If the saw wanders off line, you are probably twisting the frame out of line with the cut- If the blade snaps in the middle of a cut line, start with a new blade at the opposite end whenever possible. A new blade will be slightly thicker than a used one and is likely to jam in the old cut line.

Always use new blades to cut brass as a worn blade may slip.

Cutting sheet metal

Cut thin sheet metal at an angle keeping as many teeth in contact with the work as you can.

Blades

Hack saw blades are made with different sizes of teeth to suit the material being cut. The normal range of sizes is 14, 18, 24, and 32 teeth per in. As a guide, 3 teeth should fit the thickness of the material. Choose fine teeth for sawing thin sheet material or hard metal, and coarse teeth for soft metals like aluminum which would clog finer teeth. Coarse teeth are "raker" set for efficient chip clearance and are recommended for thick sections of soft metals. A wavy set is used for fine teeth.

Fully hardened blades are brittle, and likely to break easily in the hands of an amateur. They are also very expensive. For general purpose work, use a flexible steel blade with hardened teeth.

Hack saw blades have fine, regularly spaced teeth which can be raker set or wavy set.

Fitting a blade

Hack saw blades are held under tension by a wing nut on the end of the frame. To replace a blade, slacken the nut until the blade slips free of the frame. Hook the holes in each end of the new blade over the locating pins so that the teeth face away from the handle and apply tension. Experiment to get the right tension when fixing the blade. If it is too tight, it will arch up toward the frame, if too loose it will bend while in use and probably snap. The locating pins protrude from a spigot which has square shoulders to angle the blade in one of four positions at 90° to one another. This allows you to fit the blades sideways or even inverted.

Hack saw blades can befitted inverted or at an angle to make cuts longer than the frame normally permits, or where access space is limited.

Junior Hack Saw

SIZE: Blade length: 6in.

MATERIAL: Frame: steel; Handle: nylon, zinc or aluminum

alloy USE: Fine metal work

The junior hack saw is more convenient to use in confined spaces but must be used to make fine cuts only.

The frame and handle of the simplest junior hack saw is made in one piece from a bent steel rod. The blade, which has 32 teeth per in., is held under tension by the natural spring of the frame and held in place by slots. The pins which project from each side of the blade hold it in position once it is inserted in the slots.

Another version of the saw has a pistol grip. The blade is located in a slot at the front end of the frame, but fits into a tensioning device at the rear.

Replacing a blade

Fit the front end of the blade in to its slot; press the end of the frame firmly and locate the other end of the blade in its slot.

 

Mini Hack Saw

OTHER NAME: Pad saw

SIZE: Length: 8in.

MATERIAL: Plastic

ACCESSORY: Hack saw blade

USE: To use where a standard hack saw is unsuitable

 

The mini hack saw is a one-piece handle and frame which accommodates a hack saw blade. It will hold broken blades as well as new ones. It is used to cut metal in confined spaces which would be inaccessible to a standard hack saw. The blade slides into the handle and is secured by a screw clamp at the front end.

Sheet Saw

SIZE: Blade length: 12 to 16in.

MATERIAL: Blade.- steel; Handle: zinc alloy

USE: To cut sheet materials

A standard hack saw cannot be used to cut large sheets of material because the depth of the frame limits its reach. A sheet saw has a hack saw blade fitted to a flat metal blade which can pass through the material like a hand saw.

The smaller version has a standard 12in. blade and is used to cut fiat or corrugated steel, brass, copper and so on. It will also cut asbestos, plastic and slate. The larger saw takes a special 16in. blade with 6 or 10 teeth per in. This saw will cut thicker sheet material, thermo-plastic brick-= -and metal covered plywood.

Saw File

OTHER NAME: Rod saw, tension file

SIZE: 6 and 8in.

MATERIAL: Steel

USE: To cut meal, ceramics and plastics

A saw file is a thin, round sectioned rod which is ten-sioned in a hack saw frame. The surface of the rod is covered either with tiny hardened teeth or by tungsten carbide particles. The file can cut in any direction and will turn in its own thickness. This makes it extremely useful for cutting very intricate curves in materials which are normally difficult to work, for example wall tiles can be cut to fit around shower fittings.

Some manufacturers provide special hack saw-like frames to tension the saw file, but with special clips, they can be used in standard hack saw frames. Files are also produced with wire handles at each end to be used without a frame at all. They are extremely useful in confined spaces where a standard frame saw would be unsuitable.

Band Saw

SIZE: Depth of throat: 9-1/2 to 14-1/2in.; Table: 7 x 7 to 13 x 18in.

MATERIAL: Various

ACCESSORIES: Blades

USE: To convert large sections of lumber to size and to cut curves

A band saw is a power tool which is widely used in industry to cut lumber to size, particularly where curves are involved. Smaller versions are available for the home workshop. The blade is a steel loop which is driven around two wheels inside the casing to give a continuous cutting edge. Depending on the model, home workshop band saws will cut wood up to 6in. thick.

Blades

Band saw blades are toothed steel bands welded into a continuous loop. On the smaller domestic machines, they range from &in. to in. wide. The narrow blades are used for cutting tight curves; wider blades make straighter cuts. The teeth are spaced at 6 to 24 teeth per in. Coarse blades are for cutting through large sections of lumber, while fine teeth are for cutting metal. The shape of the teeth also varies. Like the hack saw, the band saw has standard, skip tooth and hook tooth blades. The set of the teeth also varies from blade to blade. The common woodworking blade has teeth set alternately to the right and left like any hand saw. For coarse metal working, there is often a raker or unset tooth positioned between a pair of set teeth to clear the waste quickly. Fine metal cutting teeth have a wavy set like a normal hack saw.

Toothless blades are available for cutting ceramics and plastics. The cutting edge is surfaced with tungsten carbide chips. This kind of blade will also cut lumber and board; it produces a very smooth finish but is rather slow to work.

Fitting blades

Open the wheel guards to get to the two wheels over which the blade runs. The lower wheel is driven by the motor. The idler wheel is adjustable for tensioning and sometimes tracking. Both wheels are covered with rubber to protect the set of the blade. Slacken the upper wheel tension adjuster (usually located at the top of the machine) so the blade will be able to fit easily over both wheels. Retract both blade guide assemblies as far as possible and remove the table insert. (The table has an access slot to allow the blade to pass through to the centre.) With the teeth facing you fit the blade over the wheels. Take up the tension by the adjuster.

Some saws have a scale to indicate the correct tension for each blade; if yours does not, tension the blade until it flexes no more than a Jin. sideways under finger pressure.

Blades are raked or wavy set like a hack saw or alternate set like a hand saw. Skip and hook teeth clear waste quickly.

Tracking

On some machines the blade will automatically track in the centre of the wheels. Otherwise, a tracking adjustment mechanism will be provided. Check manufacturer's instructions for the exact procedure. On machines without automatic tracking, set the support wheels about 6ldn. behind the blade. They should not be in contact with the blade until force is applied to it. Check the tracking by rotating the lower wheel by hand.

Setting the guide pins

Set the guide pins to clear each side of the blade by 0.003in. Use a feeler gauge to measure the clearance or a piece of paper as a rough guide, They should also be adjusted to fit just behind the teeth. If they are positioned too far forward, they will spoil the set. Rotate the saw by hand once more to check the settings.

Close the wheel guards and replace the table insert. The upper blade guide assembly can be raised or lowered to accommodate the thickness of the work. Adjust the guide to just clear the work's surface.

Maintenance

Clean the band saw regularly to remove the accumulated dust. Replace rubber wheel linings if necessary. Hang the blades in a loop or fold them into a coil for storage.

With the teeth facing away from you, hold the band about one third up from the bottom of the loop. Cross the band, left over right, to form three loops.

Straight cuts

Straight cues are best made against a guide fence. Mark the width of the cut on the work and adjust the fence to line up the mark with the blade. If your machine does not incorporate a rip fence, clamp a temporary softwood fence to the table. Switch on the power and feed the work past the blade with steady pressure. Use a push stick to feed narrow work efiiciently.

If the blade wanders off line, even with a guide fence, check the condition of the set and the adjustment of the blade guides.

Cross cuts

Set the mitre fence at right angles to the line of the blade to make a square cross cut. Make a trial cut on waste material and check with a try square.

Making a cross cut

Hold the work firmly against the fence and feed the work past the blade.

Mitre cuts

The mitre fence can be set to any angle up to 45 to make mitre cuts. Proceed as for square cross cuts.

Make compound angled cross cuts by using the mitre fence while the table is tilted.

Beveled cuts

The table can be angled to cut beveled rip and cross cuts. Slacken the table tilt clamp and move the table by hand to the required angle indicated on the protractor scale, Relock the table tilt clamp.

Making a beveled cut

For beveled rip cuts, position the fence below the blade so that the work is supported during the operation.

Free-hand beveled cuts can be made by removing all fences and following by eye a marked line on the work.

Curved cuts

When cutting curves, take care not to twist the blade out of line. As soon as the curve becomes too tight for the blade to take easily, run the blade out of the work on a tangential cut.

If necessary, the blade can be backed out of a cut in order to correct the line or move in another direction. Bring the blade out slowly and avoid pulling or twisting it.

Cut several identical shapes in thin sheet material by pinning several pieces together through the waste. Follow the pattern on the top sheet to cut all the boards simultaneously. Thin sheet metal can be backed up by sandwiching it between sheets of scrap plywood.

Negotiating a curve

Make a tangential cut to get the blade out. Remove the waste, and start again, making tangential cuts as necessary until the curve is complete.

Masonry Saw

OTHER NAME: Stonemason's saw

SIZE: 12 to42in.

MATERIAL: Blade: steel.; Handle: hardwood

USE: To saw through masonry

Masonry saws have carbide tipped teeth for sawing through bricks, stone, cement and building blocks. The two-man wall saw will cut a whole section from a masonry wall to insert a door or window, or can be used to cut between brick courses to insert waterproofing in an older house.

The smallest version, known as a chasing saw, is used by electricians and plumbers r channel out masonry for the insertion of cable, conduit, or pipework.

A general masonry saw is used like a hand saw to cut all types of masonry, roofing tiles, and earthenware pipes to size.

Compass Saw

3THER NAMES: Pad saw; keyhole saw; wallboard saw

SIZE: Blade length: 5 to 15ii 3 to 10 points per in.

MATERIAL; Blade: steel; Handle: zinc alloy, hardwood

USE: To cut holes in a panel

The compass saw has no frame, so it can be used in places where a coping saw, for instance, would be limited to the edge of a board or panel. The compass saw has a tapered narrow blade and can be used to cut a letterbox hole, keyhole, lock hole, or a hole for a switch plate or a socket box in plasterboard.

Some types take only one type and size of blade; others take a small raoge of interchangeable blades of different sizes, usually small, medium and large. There are also pad saws that will take whole or broken hack saw blades, which make them a useful general purpose short stroke saw.

For small diameter holes use a saw with a pointed blade; for cutting thin wood such as plywood or hardboard use a saw with fine teeth; for cutting through fairly thick panels of lumber use the wider blades.

Fitting a blade

Blades are held in place either by a knob or a screw on the ferruled neck of the handle. Turn the knob or screw counter clockwise. withdraw the blade. slot in a replacement and then tighten.

Using the saw

Drill a small hole in the wood to receive tke tip of the blade and gradually cut into the wood using a series of careful short strokes.

The thin, high grade, tempered steel blades easily bend and can often jam if the cutting action is too rigorous.

Hole Saw

OTHER NAME: Hole cutter

SIZE: Diameter: to 4in.

MATERIAL: Blade, drill bit: steel; Backing plate: plastic, zinc or aluminum alloy

USE: To cut large holes in various materials

The hole saw has a drill bit centreed on a cylindrical saw blade. The blade is either cup shaped, being pressed in one piece, or curved, and fits into a backing plate. Each set is sold with a range of sizes. Blades are made in various materials to cut wood, cast iron, sheet steel, stainless steel, aluminum, brass and plastics.

Secure the hole saw in the chuck of a portable electric drill or a drill press. Mark the centre of the hole with a centre punch, and locate the point of the drill bit. Select a slower speed than normal as the blade itself will be moving much faster than the central drill bit. Feed the saw into the work at a steady rate.

To cut a ring, set up the saw in a drill press and clamp the work to the table with a backing sheet. Drill out the centre of the ring, fit the larger blade of the set and cut the circumference of the ring without moving the clamped work.

The compass saw has no frame, so it can be used in places where a coping saw, for instance, would be limited to the edge of a board or panel. The compass saw has a tapered narrow blade and can be used to cut a letterbox hole, keyhole, lock hole, or a hole for a switch plate or a socket box in plasterboard.

Some types take only one type and size of blade; others take a small range of interchangeable blades of different sizes, usually small, medium and large. There are also pad saws that will take whole or broken hack saw blades, which make them a useful general purpose short stroke saw.

For small diameter holes use a saw with a pointed blade; for cutting thin wood such as plywood or hardboard use a saw with fine teeth; for cutting through fairly thick panels of lumber use the wider blades.

Fitting a blade

Blades are held in place either by a knob or a screw on the ferruled neck of the handle. Turn the knob or screw counter clockwise, withdraw the blade, slot in a replacement and then tighten.

Using the saw

Drill a small hole in the wood to receive the tip of the blade and gradually cut into the wood using a series of careful short strokes.

The thin, high grade, tempered steel blades easily bend and can often jam if the cutting action is too rigorous.

Reciprocating Saw

OTHER NAMES: All purpose saw, saber saw, heavy duty saw, bayonet saw

SIZE: Unloaded speed: 1,600 to 3,000 strokes per minute; Weight 6 to 8|lb

MATERIAL: Various

USE: To cut various materials

The reciprocating saw is a portable heavy duty version of the saber saw except that the blade moves backward and forward rather than up and down. It is a two-handed tool with. both a fixed and a secondary handle. The blades which can extend up to 12in. long can saw through large logs or through a wood wall to install windows or pipework. The blades can also be turned to cut in different directions and fitted to cut flush with the surface.

With the appropriate blade the reciprocating saw will cut equally well through wood, metal, plastic and composite boards. Some versions incorporate variable speeds to work all the different materials efficiently.

Using a reciprocating saw

A fixed handle incorporates the trigger switch and speed control, while a secondary handle can be turned to control the saw in a variety of positions.

Bench Jigsaw

OTHER NAME: Scroll saw

SIZE: Depth of throat: 16 to 25in.

MATERIAL: Various

ACCESSORIES: Jeweler's blade, saber saw blades

ATTACHMENTS: Files, sanding attachment

USE: To cut scroll work

The bench jigsaw is an ideal machine for the small workshop, its main advantage being the ability to make even, tight curved cuts while leaving both hands free to guide tile work. Fitted with the correct blade it can handle straight cuts in work up to approximately 2in. thick. It will also cut a variety of materials.

Blades

The blades used in a saber saw can be fitted in a jigsaw (in the lower chuck only), but the jeweler's blade is specifically designed for it.

JEWELER'S BLADES

Jeweler's blades, available for cutting wood, composites, metal and plastic, are about 6in. long and range from 1/32 to 1/4in. wide, with between 7 and 32 teeth per inch.

Fitting the blade

Raise the hold down assembly and remove the table insert. Move the drive belt until the bottom assembly is at the top of its travel. Place the bottom end of the blade in the chuck, teeth facing forward and downward, and secure it with the locking screw. Check that the blade is vertical in all directions with a try square before pulling down the upper chuck assembly and fitting the top end of the blade. Blades can be fitted parallel or at right angles to the arm, whichever gives best clearance. The blade must be correctly tensioned to cut accurately and avoid constant breakage. All machines have a tensioning device as part of the top blade fixing assembly. Generally, thinner blades require more tension than wider ones.

Blade guide

The blade guide prevents the blade twisting and bending. While the device may diifer depending on the individual saw, it is usually a slot in a disk or tube which can be adjusted to encompass the blade. A "back-up" lightly supports the back edge of the blade. Insure that the blade is free to move and runs true in the guides.

Using the saw

The work must be held down during the cutting operation. All machines have a sprung foot, adjustable vertically to take work of different thickness. Adjust it to just touch the work. Too much pressure can mark the surface and even make it difficult to feed the work. Orientate the air blower nozzle to the most convenient position.

Select the right speed for the job. Each manufacturer will supply recommendations for their individual machine. As a guide, the heavier the blade the slower the speed; the faster the speed the better the finish.

Before switching on the power it is a good idea to move the machine by hand through one complete revolution to make certain that all adjustments are correct.

Correcting faults

If the blades are breaking too frequently, check the tension and guide alignment or adjust the speed. If the cut wanders or is out of square, the guides are probably out of line or the tension insufficient. If the work vibrates excessively, check that the hold down is adjusted properly or slow down the speed.

Making curved cuts

For very tight intricate curves, use a narrow blade. Use wider blades for shallow curves.

You can make interior cuts in a sheet of material. Drill a hole in the waste through which the blade can pass. With a saber saw blade fitted, pass the blade through the hole and operate the saw. With a jeweler's blade disconnect lc from the top assembly, pass the work over the blade and reconnect. See saber saw, pages 94-95 for cutting internal square corners.

On some jigsaws the entire frame and upper assembly can be removed so that large boards can be cut un-restricted with a saber saw blade. Cut thin sheet material, sandwiched between sheets of plywood to prevent distortion and i educe burring.

Cutting tight curves

Keep up a steady pressure on the work as you feed it in. Take tight curves slowly without twisting the blade.

Making straight cuts

Fit a wide blade and clamp a Temporary fence to the table. Feed the work steadily against the fence. Use a push stick for narrow tvork.

Bevel cuts

Beveled cuts can be made by tilting the whole table. Tighten the clamp before.using the saw. Readjust the hold down assembly to suit. The hold down foot on some saws can be angled to align with the work.

Angling the table

Raise the hold down assembly, slacken the tilt clamp and move the table by hand to the angle indicated on the protractor.

Filing

Files are specially made for use with the bench jigsaw. They have 1/8in. or 1/4in. diameter shanks, which fit into the "V" block in the lower chuck only. A variety of shapes are available in different grades.

Lift the hold down assembly out of the way and remove the standard table insert. Replace it with a special insert with a 1/2in. diameter hole drilled in the centre. Check the vertical alignment of the file with a try square before you begin.

Use a slow speed for filing. Simply run the work against the file to achieve the required finish, but avoid excessive pressure. Clean the teeth of the file periodically with a file card or wire brush.

Sanding

Commercial sanding attachments are available for the jigsaw, but it is easy to make your own. Glue a gin. diameter metal rod into the end of a length of wooden dowel. Stick ad-

hesive paper to the outside of the dowel and fit the rod in the lower chuck as you would a file. Use a slow speed when operating the machine for sanding for best results.

PAPER

 

Radial Arm Saw

SIZE: Cross cut capacity: 14 to 16in ; Rip cut capacity: 25 to 26-1/2in.; Horsepower: 1.35 to 4.5

MATERIAL: Various

ACCESSORIES: Saw blades

ATTACHMENTS: Dado head, shaping and j minting head, drum sander, disk sander, drill chuck, router chuck, tool guard

USE: Multi-purpose bench saw

 

ANTI KICK-BACK ASSEMBLY

The "anti kick-back" assembly allows the lumber ro run freely while the machine is cutting, but if the blade jams the small pivoted teeth prevent it from throwing back the work.

The radial arm saw is one of the most versatile power tools available for the home workshop. It not only provides a variety of saw cuts, in metal, lumber and composite boards but fitted with various attachments, it will cut dadoes, grooves, rabbets, joints and mouldings. It can also be converted to a drilling machine and a drum or disk sander.

All radial arm saws share certain features. The motor and blade are hung in a yoke which allows the blade to be pivoted and tilted to any angle in both the vertical and the horizontal planes.

The blade actually cuts into the work table itself when in use, consequently it is advisable to cover surface of the table with a sheet of thin, easily replaceable plywood.

BLADE GUARD

The blade guard can be adjusted to cover the maximum amount of teeth for each cut. Position the guard carefully before switching on the power.

YOKE

The yoke runs on an overhead arm, which can be pivoted through 180° and locked at any angle in between. It can also be raised or lowered along with the column mounted to the rear of the machine.

WORKTABLE

The fixed worktable is fitted with two fences, the forward fence for cross cutting and the rear fence for rip sawing. Always sweep sawdust away from either fence before using the machine.

Blades and disks

There are several blades or disks available for use on the radial arm saw. The most obvious are the cross cut and rip saw blades but these are really only suitable for a long run of work. A better blade for the home workshop is the combination blade, which can make rip or cross cuts as well as bevel cuts of various kinds. The combination blade has groups of cutting teeth separated by a raker.

There is also a planer combination blade that will leave a perfectly clean finish after the cut. To produce the same kind of finish on plywood, use a plywood combination blade which does not splinter the surface veneer. If you use a standard blade to cut high glue content, composite boards, such as particle board, it will blunt very quickly. A blade with tungsten carbide tipped teeth will last up to ten times longer and will cut solid lumber as well as all the composite boards equally well.

There are various blades and abrasive disks for cutting all kinds of metals, bricks and ceramic tiles.                    _

Combination blade

This blade is the most versatile for the home workshop.

Adjusting the arm

The arm can be raised or lowered by turning the elevating handle. Switch on the machine and lower the arm until the blade cuts about 1/6in. into the table.

Pivoting the arm

The arm rotates right or left for angled cross cuts. .Release the miter clamp and lift the latch to position the arm at 90° or 45° Pivot the arm to the required angle indicated on the mitre scale. Tighten clamp.

Rotating the yoke

The yoke rotates to position the blade for cross or rip cutting. Release the yoke clamp and lift the locating pin to allow the yoke to swivel. The pin will automatically position the yoke in one of four positions at 90° to one another. Tighten the clamp before using the saw.

Tilting the saw

Elevate the arm to clear the saw blade from the table. Release the bevel clamp and pull the locating pin to allow the saw to tilt in the yoke. Read the required angle on the bevel scale and relock the clamp. The locating pin automatically locates the blade at angles of 90 and 45r and in the horizontal position.

Safety factors

Always switch off the power supply before fitting any type of new blade.

Make sure that any blade or cutter is securely fitted before switching on the saw and that all clamps are tightened.

Adjust the blade and and kick-back assembly to suit each different cut.

Keep the machine free from dust, particularly the arm tracks and bearing surfaces.

Keep your hands well away from the blade whenever the saw is running.

Cross cuts

Set the yoke so that the blade is at 90 to the work and make certain that the mitre scale on the arm reads zero. Check that all clamps are secure except the rip clamp, which must be loosened to allow the yoke to run freely along the arm. Slide the carriage to the rear of the table and set up the cross cut fence. Lower the arm. Mark the work with a try square and position it against the fence, face side up, Position the marks so that the blade cuts on the waste side. Hold the work securely against the fence, switch on and pull the blade steadily toward you. When the cut is complete, return the blade to the rear of the machine and switch off.

Cutting wide work

If the work is wider than the full travel of the saw, there are two things you can do to cut the work. If it is important to preserve the top surface, remove the normal cross cut fence and use the rip fence. Reposition the blade in the kerf and continue with the cut.

The second method for dealing with a workpiece which is wider than the saw's travel is to turn the work over and make a second cut to meet the first. It is important to set up a stop on the fence so as to position the second cut accurately.

Cutting multiples

If you want to cut several pieces of lumber to the same length, clamp a block of wood to the fence or across the table i to act as a stop. Position the first piece against the blade, butt the block against the end and ciamp it in position.

An alternative method is to lay several pieces together on the work table against the clamped stop and cut them all in one pass.

Rip cuts

To make a rip cut cut down the length of a board, rotate the yoke to position the blade nara-llel with the guide fence.

The blade can be in two positions, for narrow and wide ripping depending on the distance of the cut from the fence. Remove the cross cut fence to set the necessary width of cut. Position the blade accurately by moving the yoke on the arm, check the width of cut on the rip scale and tighten the rip clamp. For absolute accuracy, check with a rule by measuring from the fence to the blade, or make a trial cut in scrap lumber and measure the cut itself.

Feed the work into the blade from the side opposite the anti kick-back assembly, known as the "infeed" side. Position the wcrk, or a scrap piece of the same thickness, against the in-teed side of the blade and adjust the guard until it almost touches the surface. Position the work on the other side of the blade and adjust the anti kick-back assembly so that the teeth are approximately |in. below the surface of the board when hanging free. Position the teeth on the work and test them by pushing the work toward the saw: they should bite into the work to prevent its movement. If they do not, lower the assembly further.

With the work pressed against the fence, switch on the saw and feed the work steadily into the blade. For very narrow pieces of work, use a notched stick to push the last part of the work through the blade.

Wide ripping

For very wide boards it is a good idea to have someone help support the work as you feed it into the blade.

Bevel cuts

By tilting the saw, bevels can be cut as easily as a square shoulder. With the saw set up for rip cutting, any angle can be cut along the entire work edge.

Chamfers

Cut a chamfer on the edge of a board as for a bevel. Tilt the blade to 45 and set up the fence so that the blade will remove the top corner only.

"V" cuts

Make two bevel cuts which do not cut right through the work. This is an easy way to make the "V" blocks used to hold round stock for drilling.

Cross bevel cuts

To cut across the work turn the yoke to the cross cut position and tilt the saw at the same time. Work as for a standard cross cut. A beveled cross cut can be used to mitre joint the corners of a box. You can also use the beveled saw blade to cut a groove in the mitreed face to take a plywood tongue.

Mitre cuts

To mitre joint a frame, keep the saw blade in the vertical plane, but swing the saw arm over to 45'. Cross cut in the normal way to produce a inhered joint which will meet at 90°. The two halves of the joint can be cut with the saw at the same angle if the lumber is square or round, but for a moulded frame, the blade must be swung in the opposite direction to cut the second half of the joint.

Compound angled cuts

By combining the swivel arm and tilting blade,, the saw can cut a wide variety of compound angles.

Dadoes and grooves

A dado is a groove cut across a piece of lumber, while a groove is a channel running with the grain. Both dadoes and grooves can be cut with a radial arm saw by setting up the controls to make a rip or cross cut.

Cutting a dado

Lower the saw until it will cut the depth of the dado- Position the work so that the blade will make a cut for each side of the dado on the waste side of the line. Remove the waste between with successive cuts.

Cutting a groove

Move the yoke along the arm for each cut and lock it in place with the rip clamp.

Dado head

A dado head allows you to cut the entire width of a dado in one pass. The most common version has two combination blades to cut the edges of the dado simultaneously.

"Chipper" blades, with large teeth, are sandwiched between the combination blades to remove the waste. Paper washers separate the blades and allow them to be put together in various combinations to cut dados up to 13/16in. wide.

The dado head will cut dados and grooves by setting the saw up for cross cutting or ripping. Feed the work steadily through the cutter assembly.

Cutting a rabbet

In addition to cutting dadoes and grooves, a dado head can also be used to cut a rabbet. It should be used on the edge of die workpiece. Lower the dado head to the depth of the rabbet. Operate the machine for normal rip cutting, but feed the work a little more slowly. To cut a rabbet wider than 13/16in.; make a second cut by moving the yoke along the arm the required amount while leaving the depth adjustment unchanged.

Cutting a lap joint

Make lap joints quickly and accurately by setting up a dado head to cut a rabbet in the cross cut position. Cut several joints at one go by positioning an end stop across the table.

Cutting a tenon

Cut a tenon in the same way as a lap joint by turning the work-piece over between cuts.

Shaping and moulding

The saw blade can be replaced by a cutter head which takes two or three shaped knives. A three knived head will make a cleaner cut. The cutter head fits on to the saw arbor, usually with some kind of bushing, and is secured by the arbor nut.

The knives of the cutter head locate in slots in the edge of the head and are secured by Allen screws. The assembly must be protected by a special tool guard. Revolve the cutters by hand to check the clearance before connecting the saw to the power supply.

Setting up for moulding

Tilt the motor until the cutter head is parallel with the work table. Lock it in position with the bevel clamp handle, rush the assembly to the rear of the arm so that ike cutters project from the fence as required and lock in position with rip clamp. Adjust height.

Fences

The fence must nrovide maximum safety and allow the knives to protrude. A standard fence with a gap between, or a higher fence with a hole cut through it will do. (The tool guard must also be in position before the machine is used.)

Cutter head knives

There are many shaped knives for use with the cutter head. They can be used to cut edge joints, such as a tongue and groove or rabbet joint, or various mouldings. As illustrated, some of the cutters can be used to achieve more than one finish.

Position the work in relation to the cutters by placing it against the fence so that one blade is resting against the end of the work. Adjust the depth of cut by moving the yoke and lock it in position. Adjust the guard so that it just clears the workpiece.

Feed the work against the direction of cutter rotation by pressing it against the fence on the infeed side and passing it through the cutter at a steady rate. Where possible cut with the grain for the cleanest cut.

Some cutters remove a considerable amount of wood, so with some hardwoods it may be necessary to remove the waste in two passes, adjusting the depth of cut between each pass.

Cutting mouldings

To cut a moulding on the end grain, back up the work with scrap lumber of the same thickness to avoid breaking out at the end of the cut. When cutting a moulding all around a panel, cut the end grain first so that the final cut along the grain will remove all damage from splitting out.

It is often better to produce a narrow strip moulding by cutting the shape on a large board and then rip cutting it down afterward.

Where only part of the edge of the workpiece is removed, as with a rabbet for instance, the two halves of the fence should be in line. For this kind of work use a straight fence.

A different technique is necessary when the entire edge is being cut away.

Removing the entire edge

The outfeed side of the fence must be out of line with the infeed side to support the work after the cut.

Method one

Pin a strip of lumber to the outfeed fence which matches exactly the amount being cut away from the work.

Method two

Sandwich spacers between the fences and the edge of the work table to position the fences out of line. On the infeed side the spacers will be in front of the fence, and on the outfeed side, behind. They should be flush with the surface of the table.

Drilling

Most radial arm saws can be converted to a drilling machine by fitting a chuck on the opposite end of the arbor from the saw blades.

The motor, with chuck fitted, should be adjusted to the wide ripping position so that the drill bit faces the column to the rear of the machine. Make a special fence to back up the work and to raise it to the level of the drill bit.

Method of drilling

Adjust the position of the bit in relation to the work by using the elevating handle. To position the bit to the right or left, move the work itself. Clamp a depth gauge to the bit to act as a depth stop. Move the yoke toward and away from the work on the arm as for cross cutting. Lock the yoke with the rip clamp between operations. Drill holes at an angle by pivoting the arm.

Mortise drilling

To drill into end grain while mortising, adjust the yoke so that the drill bit faces to one side of the machine. Make a box to lift the work to the required height, and fit a secondary fence on the box parallel to the regular fence. Clamp the back of the box to the regular fence and carefully feed the work into the drill against the secondary fence.

Cut a mortise by drilling a series of holes in the waste and removing the remainder with a chisel afterward.

Special drilling fence

Screw a 1-1/2in. thick support to a wide upstand. The lower portion of the upstand should be clamped in the work table.

A special box-like attachment to lift the work to the proper height and a secondary fence are needed when drilling end grain wood.

Disk sanding

The abrasive paper itself is glued to the metal disk. Paper disks are available from coarse to fine grades. Make a box to raise the work to just below the centre of the wheel, and clamp it securely to worktabie or fence. Angle the fence to sand mitres. Remove the fence for free-hand sanding, but use the down side of the disk as much as possible.

Sanding end grain

Screw a fence to the top of the box so that the work is fed against the down side of the disk. Move the motor assembly along the arm to avoid sanding too long on one pari of

Drum sanding

Either fit a worktabie with a hole cut into it so that the end of the sander can be lowered below the surface, or construct a box to raise the work.

Curved shapes can be sanded free-hand against the drum which attaches to the arbor.

Sanding straight edges

Set up the drum sander in relation to the fence so that the work passes over the sander having the fence as a guide.

Other uses

The radial arm saw has several other attachments which further increase its versatility. It can be converted for routing, spindle moulding, jigsawing, turning and grinding as well as for polishing.