My uncles have some really big & heavy ones but the small set I got for my small mill(13mm slots I believe) are the imports & I've been happy with them. The threads aren't lose enough to give a spin & they free wheel but they turn easy by hand & have a close thread tolerance. I get good clamping force with no problems. I can't think I'd be any happier with a set that cost more.
I just got a new bigger mill & was thinking about making the clamps but decided for the price of $50 & I'd have the holder so I bought another import set that is probably at the house now. So I'll see if the one good set was a fluke.
I just got a new bigger mill & was thinking about making the clamps but decided for the price of $50 & I'd have the holder so I bought another import set that is probably at the house now. So I'll see if the one good set was a fluke.