02-03-2016, 05:41 PM
I'll add my two cents here. I worked QA that had to comply with milspecs and medical devices manf., both demanded certified, traceable calibration of all measuring devices. Is this necessary for a lot of the discussion here, no. But if you have a question about the accuracy of your calipers, it's easy to find out. I picked up a set of gauge blocks used for calibration at a garage sale. Or, stop at reputable machine shop, odds are they have a set gauge blocks and ask them to check your calipers.