Problem 4-15

4-15. The screw of the clamp shown has a single square thread, a mean diameter of 12 mm, and a pitch of 3 mm. If the clamp is tightened with a torque of 1 N·m and µ_s = 0.25 between the threads, determine (a) the magnitude of the force pressing the two pieces of wood together. (b) the torque required to loosen the clamp if self-locking exists.