1 1/8 -8 UNC modeled thread fails. Patterned thread works. The following image shows 1 1/8 -7 UNC modeled thread is successful and the 1 1/8 modeled thread fails.
Repro file attached.
ETFrench
1 1/8 -8 UNC modeled thread fails
Hi @etfrench
Thanks for posting! I was able to recreate the issue you described in your file as well as in a new file. I looked into this a bit and found that I could not find any reference to the 1 1/8-8 UNC specific threads in any mechanical engineering resources (including the Machinery's Handbook).
The 1 1/8-7 UNC and the 1 1/8-8 UN threads were present in the charts and worked properly when modeling threads in Fusion 360. I think that the issue here is that Fusion includes the option to define a non-existent thread. I have logged a request with development to remove this thread option from Fusion. If you are able to find charted thread data for a 1 1/8-8 UNC thread please send me a link on this forum thread!
Please let me know if you have any questions - I'm happy to help!
I think 1 1/8 x 8 UN is the correct definition and the UNC definition should be removed.
ETFrench
Hello @paul.clauss @etfrench
There is no UNC definition that I know of.
Here is a pic of a Unified Screw Thread table:
