Force required to pull a threaded tube from its socket

[beartato]

Hello everyone.

I have been trying to determine the tensile force needed to rip a threaded tube out of its female threaded socket. After some Google searching, I found this:

http://www.engineersedge.com/thread_strength/thread_bolt_stress.htm

I used shear area, which I believed to be an "equivalent" cross-sectional area of a bolt, and multiplied by the ultimate strength of the material to calculate force necessary for failure. However, my numbers ended up being way too high.

Perhaps I misunderstood the meaning of shear area; this calculation would not work if shear area is not perpendicular to the axial force that I am trying to get. I have looked around for other ways of solving my problem, but haven't had much luck, and so decided to post here for some inspiration. Any advice would be appreciated.

Thanks in advance!

 

[Robot B9]

The area you used should not be the problem, the strength is. It is much more reasonable to use Yield strength. At yield the material will be permanantly deforming. This will give you a low number but its safer this way!

 

[sardonicus]

If your thread length is at all generous your bolt will twist off or fail in tension before the threads shear off. You have two other checks, tension on the net area, and shear due to torque on the net area, one of these two typically governs. S