What's the right fit for M27x0.5 threads? I created several test pieces to try out different threads that I'll use for a custom threaded watch back. I'm using aluminum for these tests and will switch to stainless steel for the depth tests that will come soon.

My Thread Calculator on Patreon:   / metric-threads-74939382  

Blog post with the simplified calculations: https://trains.socha.com/2022/10/metr...

Video on threads:    • Threads and tolerances, calculating d...  

00:00 Intro
00:53 Test Case and Back
03:03 Normal Fit, 6g & 6H
05:10 Custom Form Tool
06:49 Fusion CAM Simulation
08:06 Milling Test Coupons
10:50 Trying the Test Coupons
11:52 Tighter Threads
13:19 Comparing the two fits