A rotary milling cutter has a cutter body mountable on an adapter. A first side of the adapter is provided with circumferentially arranged drive pins centered about a centrally positioned, conically tapered male locating member. A first side of the cutter body is provided with circumferentially arranged drive grooves centered about a centrally positioned, conically tapered female locating member. The drive pins have a base portion connected to a head portion while the drive grooves have an insertion portion connected to a retaining portion. During assembly, the first side of cutter body and the first side of the adapter are first moved into an initial mating position in which the drive pins enter the insertion portions of the drive grooves and the male locating member enters the female locating member. The cutter body is then rotated relative to the adapter such that the drive pins enter the retaining portions of the grooves. With the adapter retained in an inverted position with its drive pins extending vertically downward, the cutter body may thus be supported by the heads of the drive pins. A center bolt normally resident in a throughbore of the cutter body is then screwed into a threaded bore formed in the male locating member of the adapter.