I've used 1/4" threads on mild steel. It's more than reliable enough and it would be handy to use it for 3 /8 threads recommended Good value for money.
The tool meets all the requirements. Made from quality materials and seems sturdy enough for whatever I'm going to use it for. This made refilling the handpiece for my Grizzly Wet Stone Sharper a breeze.
First use I pushed on the set screw and it broke off. The material is something like a pan. I know better than to overtighten the screws and I haven't done it. I think the carving sucked in bad tool metal from the start. It goes in the trash.