A rotary cutting tool includes a disc-like central body having an outer peripheral surface. A peripheral support member extends circumferentially along the peripheral outer surface of the disc-like central body and provides support against centrifugal and cutting forces exerted on an insert pocket during a cutting operation. A radial support member extends radially along the disc-like central body to the peripheral support member. The radial support member structurally interacts with the peripheral support member to provide additional support for the insert pocket against centrifugal and cutting forces exerted on the insert pocket during a cutting operation. The radial support member and the peripheral support member have a three-dimensional topology that maximizes a stiffness-to-weight ratio of the rotary cutting tool. The rotary cutting tool may include a second radial support member extending radially along the disc-like central body to the peripheral support member.