Autonopedia

A

First upset one end of the ^5/8" round bar to a diameter of about ^3/4".

The head of the bolt is made by welding on a collar made from ^3/8" square.

This is a tricky weld, so it is better to use wrought iron for the collar as this gets hot quicker than the bolt.

(Wrought iron, remember, will stand a higher temperature than mild steel).

Next, cut the end of the ^3/8" square to an angle of 45° so -

B

Hold the square bar over the tip of the hick with the point upwards and bend it into a tight circle.

The metal will stretch while this is being done bringing the oblique end about square with the side of the bar.

Fit the collar over the upset end of the round bar and after allowing for a gap equal to the width of square metal, make a chisel mark like this -

C

Take a BRIGHT RED heat, cut off the bar at the chisel mark and fit the collar over the upset end of the ^5/8"bar.

D

Close the collar tightly around the bar and return to the fire.

Take a FULL WELDING heat very slowly so that the heat penetrates to the centre of the bar without burning the collar.

E

The ends of the collar must join at one corner of the hexagon.

To close the ends and at the same time form the hexagon, the order of the first three blows is most important.

Strike the first blow a little back from one end of the collar. This will partly close the gap. Before each of the next two blows, give the bar one-sixth of a turn.

This will close the gap and the hexagon will form automatically between the hammer and the anvil. To complete the welding take a further heat.

All subsequent blows must be delivered on the flats of the hexagon.

F

Before cleaning up the body of the bolt, true up the hexagon on the anvil face.

Then lay the shank in the swage, and true up the diameter.

Keep the head central and at right angles to the shank.

G

On all bolts the thickness of the collar should be half the diameter of the bolt or a little more according to the sizes of metal available.

In each case, the gap left is equal to the width of the square metal used for the collar.