HOW TO CALCULATE TIGHTENING TORQUE FOR A SCREW IN AN ASSEMBLY?
Shigley provides the classical analysis to determine bolt torque--this can also be found in the Bolted Joint Handbook. However, the errors in these calculations swamp the results. Fastenal's results are empirical. Empirical is good.
I couldn't get a link to the Fastenal text (whether it was meant to be linked or not), so I added it below:
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