Bolt gauge with thread pitch identifier (metric and SAE)

Find bolt thread pitches without threading them into internal thread checkers!

Standard thread checkers where you thread the bolt into some internal threads can be problematic. When it's a close fit, it's hard to tell if a bolt is the wrong size, or it's just cross threaded or stuck. Or for very similar bolts, you can thread the bolt in 5-10 turns before it binds, and then it's hard to tell if it's just a cruddy bolt or the wrong size.

This thread checker avoids that by allowing you to quickly check about ½ inch of threads without threading the bolt into a checker. The bolt will very positively fit fully into the correct thread pitch, while it will fail to fit into the incorrect threads.

Also includes holes to identify the diameter of the bolt, and a groove to hold the bolt easily with a rule to measure the length.

This was a bit of an experiment, the finest threads are the most challenging fine details I've attempted to 3D print so far. The smallest bolt I have to test with has 32 TPI, but it very clearly matches the checker, and the finest 48 TPI checker looks like it should work fine. The two finest metric threads (0.35 and 0.45) probably aren't usable with my printer/print settings. 0.5 looks usable though.

Printed on a Prusa mk4 using the included 25g PLA samples with standard settings. Printing it face down gave much better results than face up. However, the finest threads on the metric checker did get flattened out. It's possible printing these face up would work better.