parameters in xml file for custom thread

[lu_zhengYAWZ6]

Hello,

I'm trying to create my own xml file to make a custom thread M32*0.75. I used a few thread calculators but with the tolerance (6g, 6H, 4g6g), they give me a range (min and max) for major/pitch/minor diameters, rather than one definitive number as in Fusion360. And the number from Fusion is not always the average of the min and max. Can someone help explain how Fusion360 determines those specific numbers? Below is one example with numbers from thread calculator and Fusion360 for M30*0.75 thread

[MRWakefield · Accepted solution]

I've done quite a bit of work with Fusion thread files and i can confirm that the values are as far as I've experienced the mean of the max and min values. Some calculators and reference tables give different values so that might be where your observed differences come from. At the end of the day I wouldn't worry if there's a few microns discrepancy as the sizes aren't really used in any manufacturing process except for 3D printing. Obviously a few microns here or there when 3D printing isn't an issue.

I've developed a Windows application for working with Fusion threads which you might find helpful. You'll find a link in my signature to a forum thread explaining the application with a link to download it. There's a metric and UN thread calculator included. I can't guarantee all calculations are micron perfect but I believe it's fit for the intended purpose.

Hope this helps.

[lu_zhengYAWZ6]

Thank you so much!

[MRWakefield]

You're welcome. If you need anything else or have any problems just shout.