1/2-5 acme 2G internal thread

[amechaman]

I have to cut a 1/2-5 acme thread in 17-4ss. I am having trouble finding taps and thread mills for this thread because the pitch is so coarse for the size. Any suggestions would be greatly appreciated.

 

[eromlignod]

Are you also making the mating screw?

Perhaps you could talk them into a double-start screw. This would give you the required lead (.200 per rev.) yet would yield normal-depth threads. It would look like a standard 1/2-10 Acme thread, but with a steeper helix.

Don
Kansas City

 

[nickelkid]

amechaman,

eromlignod is sending you in the correct direction. A good handbook will validate why you are having "trouble"

 

[eromlignod]

Incidentally, you can buy a 2-start, 1/2-10 nut right off the shelf (McMonkey-Carr has several versions) and weld/press/fasten one into your design. Again, it depends on whether you also have control over the screw selection.

Don
Kansas City

 

[terrabul1]

The best method to produce this internal thread in 17-4 is to hot form it using dies.Then you should be able to machine the required outer configuration. The external thread should be done by thread rolling.Thread roll shops should be able to do both.
Cutting this thread is going to destroy alot of special taps.