Extracted text: A7/8-in.-diameter screw, having a diameter at the root of the threads of 0.731 in., is used to fasten two timbers together as shown in Fig. below The nut is tightened to cause a tensile stress of 18 ksi in the bolt. Compute the shearing stress in the head of the bolt and in the threads m 1/2 in 15/8 in