Cutter for engagement with an arbor

A cutter (32) is for driven engagement with an arbor (fig.26) having one of an extending member (fig.42) and a pair of set screws (fig.44). The cutter (32) includes a shank portion (34) having a central axisc and a cutting portion (36) extending from the shank portion (34) along the central axisc. A retaining recess (48) is formed in the shank portion (38) for selectively receiving the extending member (42) of the arbor (26) when the arbor is configured to have the driving device (30). A pair of flats (50) are each formed in the shank portion(34) for engaging the set screws (fig.3 : 44) when the arbor (fig.1 : 26) is configured to have the set screws (fig.2 : 44). One of the flats(50) extends in a first plane (fig.6 : Pl) and the other of the flats (50) extends in a second plane (fig.6 :P2) perpendicular to the first plane (fig.6 : P1).