Shear on a bolt ?? please help?

Convert the kW to torque and moment about the shaft. Decide the moment arm to your bolts. Since its a 40mm shaft the coupler plates are larger to give enough room for the bolts. Say you use 4 bolts with a 15 mm plate beyond the shaft, the coupler plate is then 20+15 = 35 to the outside radius of the plate and you can try a 5 mm bolt maybe at 27.5 rad at the bolt center so its centered in the plate ring. So then you have the torque moment divided by 4 bolts at 27.5 moment arm you can get the load on the bolt and the bolt area by the allowable shear for the type of bolt must = the torque moment. Iterate till you balance adjusting the number and dia of bolts and even the radius of the coupler plates. Your solution should finalize on a reasonable number of bolts that will fit the coupler plates at a resonable radius and resonable spacing between bolts.