Hardening and tempering: All lathe tools of this type are hardened and tempered in the same way as you did the cold chisel. The temper colour of this tool is a very light straw. When this colour reaches the extreme point plunge the tool into water. The slight change of temperature does not materially lessen the degree of hardness, but it does toughen the tool so that it will do more work.
Diamond point
Diamond point: The form and dimensions are given.
Stock: 7 × 7⁄16 × 7⁄8 ins.
Side tool
Heat one end and bevel it off as you did when making the round nose tool. Place the other end in the fire, 5⁄8 in. from the end, and fuller down to one half the thickness of the bar. This fullering is done on the bottom fuller, which is placed on the anvil. Re-heat this end, place it again on the fuller in the depression made, and with the hand hammer draw this end out and at the same time square it up into a diamond point by turning the tool at an angle of 45° with the anvil. Turn again, in exactly the opposite direction. Repeat this until the point of the tool is drawn out as shown by the sketch. The clearance should not be more than that shown. It is now cut off by placing the face of the diamond on the outer edge of the anvil. Place the cold chisel above this edge, strike the chisel with the sledge hammer and cut it off. If this is carefully done it will cut the proper bevel for the cutting edge. The drawing shows the slope of the cutting edge to be parallel to the top of the tool. The tool is hardened and tempered the same as the round nose tool.
Side tool (right hand): The form and dimensions are given here.