It may come as a shock and surprise to many, but the $20 Chinese calipers are just as accurate as the $100+ brand name ones. They may not work quite a smooth or look as nice, but they do the job. I have a Brown & Sharpe dial caliper I bought at work some 20 years ago. Later they made us take our calibrated tools home to save the company money (company checked them every six months and kept them logged in the company system). Now I'm not sure how my walking to the tool room, checking out a caliper and returning it a couple of times a week, saves the company money over my having one right at hand in my tool box and them checking it twice a year, but I ain't the boss.
Anyhow, I have the B&S at home, but hate to use it, too nice and too much trouble to dig out of the case every time. Need to buy a cheep China one to use for the easy stuff.
Charles