Another thing that I noticed about the Chinese vise is that the holes to fasten it down to the mill table are not slotted out, so unless one slots them out, you have to lift the vise over the T bolts, or use allen or hex capscrews to hold it onto the table, which encourages chips to jam the threads. I use T bolts and never have to remove the nuts, just slide them into the slots and into the vise slots and tighten them. I use nuts hat have an integral collar, like a washer, so that the (otherwise) hex nuts would tend to chew the top of the slot up. Another thing is that the top of the holes is not spotfaced, so you are tightening against a raw casting. I did not look to see if the American vise is finished in that location, but assume that it would be.