Question for you mathmaticians

[wingnut]

I know we have some very intelligent folks here, and I have a question that I hope someone can help with. I haven't researched this anywhere else yet cause I felt certain I could get an answer here, or at least some direction where to start.
What is the formula for calculating the compression force between 2 objects that are bolted together? Example; propeller to crank flange, six half inch diameter bolts torqued to 45 ft/lbs. What would be the compression force in psi? I know thread pitch (so lets use a standard AN8 bolt, 20 threads per inch) and friction of the threads (depending on type of nut; self locking or not) and rotational friction during torquing would factor in. Any help would be much appreciated.

[ronjenx]

This calculator will give you an estimation of the clamping force of each
bolt. http://www.engineersedge.com/calculator ... e_calc.htm
Multiply the value calculated by 6, divide by prop hub contact area, should get you a ballpark figure in psi.

The calculator assumes a lot. On the page, click on "Torque Design" near the top of the page for more information.

[wingnut]

Thanks, I'll check it out