Adding UNS threads

[d-schmidt]

I'm missing the US microphone thread (5/8" - 27 UNS).
UNS uses the same 60° flank angle like other UIS threads so I naivly assume it would be rather trival to add them all or at least the microphone one?

https://www.gewinde-normen.de/en/unified-special-thread.html

[adrianschlatter]

Indeed, these threads are not included in threadlib. I'd like to invite you to add them :-) These documents could help you get started: Design of Threadlib, Creating Thread Specs

[d-schmidt]

Is there more to it than copy pasting the diameter/tpi into the UIS_thread.csv?
The guide doesn't offer much technical detail for a complete beginner. This is the first time I've seen an awk file? What does the existing UIS_thread.awk do? It is hard to understand what is happening without comments and single char variables.

[adrianschlatter]

I guess there is a bit more to it than copy and paste. You'd have to find out the basic shape of the thread. This is probably easy: So far, a trapezoidal shape (4 points) has worked for all thread types.

Then you'd identify the tolerance ranges so that you can aim for the center (=> pen&paper work). If you are lucky, UNS threads indeed use the same formulas as UIS but you'd have to check. These formulas are then implemented in a .awk file that translates a spec table (as in your link) to threadlib specs.

Regarding awk: It translates an input table into an output table. Tutorials and documentation are available on the internet. As you can see in the design/ folder, I wrote separate awk scripts for each type of thread. I expect you'd have to write a new one for UNS, too.