Forged Lathe Cutting-Off (Parting) Tool

A cutting-off or parting tool cuts a narrow groove in work turning on a lathe, and so cuts it off. It is forged from 1/2 × 1-inch tool steel 7 inches long, with a thin blade about 1½ inches long set flush with one side of the bar. Because it cuts only at its very end, the blade is made thickest at the edge and tapers back, so its sides clear the groove. It is hardened like a cold chisel and tempered to light yellow.