Don't forget that some metal clevices are 2--56, and some are metric thread. Don't mix metric clevices with SAE rods, or vice versa--you'll have problems. They are a close fit, but just loose enough to eventually "chew through" or "strip out." At least that's information that i've received. I always make sure now that my clevices match my rods. I prefer metal clevices--much easier to adjust.