Most of the time I use a vernier caliper like the above, they are accurate to damn near a thou, and if you pick "the right model" they are inch as well as metric. Get on Egag and find an old Craftsman. You should find one for 20-40 bucks. You normally want decimal and metric, not 1/128" No gears to strip, no batteries to wear out. Nowadays, I need a magnifier to read one. Speaking of which, I found some Bausch and Lomb "matchbox" magnifiers, at my age they are a necessity
Here are two examples of old Craftsman. One is decimal and 1/128, the other is decimal and metric