Thread shear help
Thread shear help
(OP)
I am looking to find out at what ft/lbs or in/lbs the threads in the aluminum will shear/strip. I have a steel post going into an aluminum plate, the thread is ¼-20 the aluminum is tool and jig. I am guessing it has a shear strength of around 30ksi. What is the equation I would use?
Here is a pic of what is going on
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Here is a pic of what is going on
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RE: Thread shear help
F=Su*Ats
Su= Ultimate shear strength of the plate or bolt
Ats=cross section where shear occurs
Assuming the plate is weaker than the bolt material the simplified expession for shear area (from FED-STD-H28) is:
Ats=3.14159*En*(3*Le/4)
En=the min pitch dia of the bolt
Le=Sst(2As)/Snt*3.14159*n*Dsmin((.5n)+0.57735(Dsmin-Enmax))
RE: Thread shear help
Your estimate of the aluminum’s shear yield strength looks quite high. 6061-T6 or T651 would be 23.1 ksi; MIC-6 would be 8.6 ksi.
There’s a wealth of useful thread information at:
http://euler9.tripod.com/bolt-database/23.html