Any idea where I can find the limits for the 60° Angle and Root Radius on a .4375-20 UNF-3A thread? I've searched the Handbook with no luck.

Thanks for any help in advance.

Courtesy of a printing in Smith's 'Nuts, Bolts, & Fasteners.'

Best,
Drew

Drew,

Thank you for your reply. Perhaps I am not seeing the obvious. I am interested in the actual tolerance for the flank angle i.e. 60°±X° and the same for the root radius.

Is the interpretation that these features exist within the profile of the spec?

If yes, then this become a pretty complicated tolerancing scheme.

I just checked in Machinery's and it doesn't have tolerances for the specifications either. Looking at a mil spec catalog the call-out for thread is MIL-S-7742, which was replaced with SAE AS8879. A little googling didn't come up with a copy of that, but you can buy that spec document from SAE.

quote:

the call-out for thread is MIL-S-7742, which was replaced with SAE AS8879. A little googling didn't come up with a copy of that, but you can buy that spec document from SAE.

Here's the Mil-Spec:

http://assist.daps.dla.mil/docimages/A/0000/0000/6581/0...06305770d12737791224

Assist is awesome for looking up mil specs for free...