force in foot pounds to shear a 5/16 AN5 -5 bolt?

Question

4 of the above bolts tie two tubes togerther. They are tied to a rear, the other to a transmission. The output shaft to rear is turning 3000 rpm and the torque is 900 foot pounds. Will that shaft 900 foot pounds transfer to the tubes enough to shear the 4 aircraft bolts

Answer 1

To determine the shear load on the bolts, the torque must first be converted to a load (Lbs.),

The shear stress in the bolts can then be calculated by dividing the shear load in the bolts by the cross sectional area of the bolts.

You will need the diameter of the bolt circle that the bolts lie on to determine the shear load from the torque value.

For example if the bolts are on a 6" bolt circle the total shear load is 900 foot pounds x 12 = 10;800 inch pounds/6 inches = 1800 pounds on 4 bolts.

If the area of all 4 bolts together = 0.307 sq. inches, then the shear stress is 1800 inch pounds/0.307 sq. inches = 5,863 psi.

If the bolt circle diameter is only 3" instead of 6" the stress would be double the value calculated above.

These stresses are not very high, and the bolts should be OK.
Try to use a bolt that is not threaded all the way up to the head so that you are not loading the threaded area of the bolt in shear.

Answer 2

The rated shear strength of an AN-5 bolt is 5750 lb.

Your ? can't be answered without knowing the radius in inches of the shear plane. The torque capacity of each bolt will equal 5750*r inch lb.