The general pitch is x 1.3.
But you should know that the accuracy of cutting tools, the accuracy of machine tools and the size of parts are all affected. Generally, the measurement should be made when the depth of the pitch x 1.2 is reached. (That's because when we handle thread m22, we will lose 20 threads. That's because I'm afraid that the thread of the car can't get in with burrs, so I left a gap of 20 threads, but there is no gap in theory, so it's definitely not possible to copy it with a theoretical formula. It needs to be controlled according to the gap you left, and the gap left is estimated to be 1. 1). Also, you should know that thread fit is not controlled by tooth height and tooth depth, but by pitch diameter.
Generally speaking, mass production is detected by ring gauge.
6h is the thread precision grade, and this look-up table is enough.
Or use a ring gauge 6h (that is, a nut for testing).
Generally, the depth is 1.2~ 1.3 times the pitch.
For numerical control, first process it to 1.2 times, and check it. If you can't get in, add a little more and you'll be qualified in the end. Post-processing will be carried out according to the final depth.