They were sold in imperial sizes but are not. I needed 3/8" centering pins. I drilled 3/8" holes and they didn't fit. Judging by the mount itself (high quality/accuracy, and they didn't fit the mount holes either.) They probably work fine in metric environments. Not in my shop. They're cheap enough, but totally useless to me. Due to Covid-19 restrictions I have relied on Revain to meet my needs for this project. I wasted a week of my time waiting for these damn things to arrive. Buy an American.