Stub ACME Thread Form Limits
Stub ACME Thread Form Limits
(OP)
By defination the stub ACME thread form has an included 29 degree angle. Does anyone have any experience in rounding slightly the upper crests of the thread to break the resulting shart corner?
How much rounding can you do and still conform to the standard?
Have male thread in F51 running in a female thread in 4130 (much softer). Concern is that the sharp edges of the male threads will bite into the female if there is any misalignment. Suggestion is to round the threads slightly to break the sharp corner, but QA has concerns that this will deviate from the standard thread form and will bear certification issues.
Thanks,
Andy
How much rounding can you do and still conform to the standard?
Have male thread in F51 running in a female thread in 4130 (much softer). Concern is that the sharp edges of the male threads will bite into the female if there is any misalignment. Suggestion is to round the threads slightly to break the sharp corner, but QA has concerns that this will deviate from the standard thread form and will bear certification issues.
Thanks,
Andy





RE: Stub ACME Thread Form Limits
I haven't looked at it for several years (and when I did it was in the UK version) so can't remember off the top of my head. However I'd expect their to be limits defined, if not explicitly then implicitly.
What we did do on ACME threads to stop problems from misalignment is remove the partial lead in thread until a full thread form was achieved. This was on a male thread, I can't remember what the mating female thread had as we didnt' design that part, on a large locking ring.
RE: Stub ACME Thread Form Limits
RE: Stub ACME Thread Form Limits
RE: Stub ACME Thread Form Limits
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RE: Stub ACME Thread Form Limits
The values refer to the actual flat width.
I didn't see anything in MH about chamfers on Stub Acme.
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