tapped hole minimum wall thickness

[lodhss]

Trying to figure out how to calculate the minimum wall thickness of a tapped hole. I’ve seen stuff for sheet metal, but not for a solid block. Right now, the wall thickness is approx 0.25 x set screw diam. The set screw would be torqued to max holding power. If you have any helpful info, that’d be greatly appreciated!

 

[KENAT]

Please don't double post.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Wrenchbender]

Naturally there are variables such as the type of material, modulus, poisson ratio, strength, length of thread engagement… However without modeling it, you could prob calculate something reasonable. Assume the failure mode for a too-thin wall would be splitting across the hole when the setscrew is torqued. If the ring fails thus in bending from a point load imposed on the inside of a ring, etc., you can take it from there. Otherwise I would keep the wall thick enough so the head of a similarly sized cap screw would not overhang. Some sources I've seen offer empirical guidelines. (Search " minimum wall thickness threaded hole".) You might also check with a fastener manufacturer.