"The threads should come out clean unless your tool is improperly set or improperly sharpened. Not enough clearance beneath the top cutting edges can cause the tool to rub on the part, which generates tightly bound smeared roughness. Even a properly sharpened tool will smear the work if it is set with the top face of the tool above the spindle axis centerline. Set the toolheight using one of the lathe centers as a reference.

Cutting dry can also cause torn metal buildup on the tool. For hobbyists, a bit of lard is probably the handiest lubricant to come by for threading."





Hmmmm you're probably right, I did set it kind of quick. Let me reset the hight and try again. I'm also using WD40, not sure if this is good or not, but kind of helps.