I have a scenario I would like to get double checked. I have a shaft spinning at 1800 rpm driven by a 500 hp electric motor. I am bolting another drive shaft to it with (qty 8) 3\8 dia shoulder bolts on a 4-1/4" bolt circle. The bolts have a shear strength of 10.5 ksi. The stresses on the bolts are purely shear as all the other forces and mitigated by other means. I am assuming a uniform load on all 8 bolts and I am ignoring starting and just focusing on the running state. I came up with a safety factor of 9, but I seldom venture into this realm and you like a sage guide to confirm the path.