Design a clamp coupling for transmitting 25 kW at 300 rpm. Allowable shear stresses in shaft and key are 50 MPa and 45 MPa, respectively. The number of bolts joining the two halves of muff is 4. The permissible tensile stress in the bolt is 70 MPa and the permissible crushing stress in the key is 90 MPa. The coefficient of friction between the muff of the CI and the shaft of steel is 0.20. What is the design of the clamp coupling?