1. The document describes a clamp or compression coupling, which uses two halves of a cast iron muff that are bolted together around the abutting ends of two connected shafts. A single key fits in the keyways of both shafts to transmit power. 2. Design considerations for this type of coupling include sizing the clamping bolts to withstand the frictional forces between the muff and shafts, which transmit the torque. The proper bolt root diameter is calculated based on these frictional forces. 3. Tolerances for misalignment are provided by a bushed-pin flexible coupling. It uses rubber or leather bushes around coupling pins to connect two flanged halves with some clearance, absorbing misalignment