So I’ve assembled a collection of micrometers and vernier calipers of varying quality, and it’s time to dive in and measure some very small things. Some of you will be metrology enthusiasts ...

A simple, fairly accurate, and easily-made apparatus of the micrometer form may be constructed as follows: Get a common iron or brass bolt about y of an inch in diameter and about 2% inches long ...

DIYers seldom need to measure with micrometer accuracy. A caliper — a ruler with sliding jaws — can perform many of the same ...