I tried to cut a 3/4" copper rod but it didn't work. The tool is poorly designed, the 3/8 x 1/2" body is too thin and the tool will flex under load and generally not cut. Maybe with thicker tools, more than 3/4, it could be better. If you need a parting tool for a small lathe that requires a thin-bodied (3/8 inch) tool, don't buy it. I'll try to weld some rebar on top of the fuselage and see if I can use it.