Nut, M12

Perfect fit on my SC4 lathe's cross-slide, and the threads engaged smoothly right out of the package. No burs or slop, just a solid, snug fit.

The threads are clean and precise—screwed right onto my SC4 without any binding or wobble. It's the exact same profile as the original part that wore out on my lathe.

I was a bit nervous about swapping this out on my SC4, since I'd never replaced a thread nut before, but the M12 fit perfectly and the whole assembly felt solid immediately. It's nice that it matches the original spec exactly, so I didn't have to do any extra fiddling.