Forged Cold Chisel

A cold chisel cuts cold metal, so its edge must be hard and its body tough. It is forged from octagonal tool steel: the head end is tapered, the blade drawn out at a yellow heat and finished with a flatter just above the hardening heat. Only the edge is hardened, by dipping it in water while the body stays hot, and the heat left in the body then tempers the edge; it is cooled when the edge shows blue tinged with red, about 570 °F (300 °C). The edge is ground to 60°.

中级

1–2 hours

说明

Taper the head

Heat the head end to a yellow heat and taper it.

此步骤所需材料：

工具钢八角钢1 个

所需工具：

铁匠炉

铁砧

锻打锤

铁匠钳

Forge the blade

At a yellow heat, draw out the other end into the blade over the anvil's edge. Finish with a flatter just above the hardening heat; hammering it when black crushes the grain.

所需工具：

平锤垫铁

锻打锤

铁砧

Cut and cool slowly

Cut the end square, or nick it and break it off after hardening to see the grain. Let the chisel cool slowly to relieve stresses from the forging.

所需工具：

热錾

Harden the edge

Reheat about 3 inches back from the edge, the edge kept high in the fire. Lower the edge into clean water at about 70 °F, moving it, until about half the heated part is under; plunge briefly and lift out with heat left in the body.

所需工具：

铁匠炉