Yes, the weak link is definitely the tapped hole in the aluminum. I calculated the "Length of Engagement" to be .479" minimum for the 10-32 thread (based on Shear Area for each thread, external vs. internal).
Shear area of Ext thread * Tensile strength of screw materail / Shear area of Internal...
THanks for the reply. I am usign Aluminum 6061 (tensile 35,000)for the clamp plate. I am compressing twelve die springs to develop 1320 lbs of force. The four Soc Hd Screws are 10-32 (grade 2)low-med carbon steel and the use is static.
I would like to have a safety factor of 2X or 2500 lbs.
I AM USING A STEEL SOC HD CAP SCREW IN ALUMINUM. I AM TRYING TO CALCULATE THE THREAD ENGAGMENT NEEDED TO ENSURE FOUR 10-32 SCREWS WILL WILL HOLD A RETAINING PLATE WITH 1320 POUNDS OF SPRING LOAD OR IF A LARGER SCREW IS NEEDED.
