The C clamp shown in the figure for Prob. 8–7 uses a 3/4 in-6 Acme thread. The frictional coefficients are 0.15 for the threads and for the collar. The collar, which in this case is the anvil striker’s swivel joint, has a friction diameter of 1 in. Calculations are to be based on a maximum force of 8 lbf applied to the handle at a radius of 3 1/2 in from the screw centerline. Find the clamping force.