JohnSL - Random Products | Threads and tolerances, calculating diameters and pitch diameter offset @JohnSL | Uploaded October 2022 | Updated October 2024, 2 hours ago.
I needed to create some custom threads and therefore needed to calculate the outer diameter for the screw, the inner diameter for the nut, and the thread depth for each. I didn't find a single source that clearly explained how to calculate these numbers, so I created this video to simplify screw and nut threads. This mostly covers metric, but can be applied fairly easily to imperial, as tolerances are a little simpler in imperial.

Blog post with the simplified calculations: trains.socha.com/2022/10/metric-threads-and-tolerances.html

Affiliate link for Machinery's Handbook 31st Edition: amzn.to/3SSeujX

00:00 Intro
02:26 Machinery's Handbook
04:08 Pitch Diameter Offset
04:34 Numbers we Need
05:40 Tolerances
07:36 Screw/External Threads
09:55 Final Screw/External Dimensions
10:30 M27x0.5 Example
12:48 Nut/Internal Threads
14:30 Final Nut/Internal Dimensions
14:49 Sanity Check - Validating the Equations
16:18 Summary