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UNEF Thread Specification Geometry

UNEF Thread Specification Geometry

UNEF Thread Specification Geometry

I'm looking through the UNEF thread specification standard and have a question.

I'll use .625-24 UNEF-3B for this discussion. The standard defines the minor diameter as .5800-.5869. The standard defines the pitch diameter as .6018-.5979. The standard defines the major diameter as .6250 minimum. I do want to make sure I don't end up with a thin wall in my threaded part. What dictates the maximum allowable major diameter?

I have the same basic question on the .625-24 UNEF-3A thread standard. What governs the minimum allowable minor diameter if the maximum allowable minor diameter .5739.

RE: UNEF Thread Specification Geometry

The thread form as located by the pitch diameter.


RE: UNEF Thread Specification Geometry

Thanks Ted.

RE: UNEF Thread Specification Geometry

The maximum diameter is limited by the thread angle from the max pitch diameter. That's why it's not toleranced in standards. Pitch diameter is the important bit.


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RE: UNEF Thread Specification Geometry

Thanks Pud. I understand now.
I found some online calculators that are most helpful.

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