u2032 and radially interior to end sections 48 u2032 and 50 u2032 turning now to fig7 10 drum teeth assemblies 44 cutterhead teeth assemblies 90 and guard teeth assemblies 96 and 98 constructed in accordance with embodiments of the present invention are shown in detail it will be understood that aspects of the present invention may be used in conjunction with prior art features shown in fig1 6 each of the teeth assemblies 44 90 96 and 98 may include a pair of individual teeth 118 which beneficially are common to each of the teeth assemblies 44 90 96 and 98 to reduce the number of parts which must be maintained in inventory thus the exploded view of fig8 shows the same individual teeth 118 which are used in each of the teeth assemblies 44 90 96 and 98 and which are mounted to the respective mounting plates 62 flanges 92 and ear plates 100 102 the individual teeth 118 may be provided with a substantially flat back side 120 and a raised or somewhat convex front side 122 and have a point 124 upon which converge two serrated cutting edges 126 and 128 holes 130 are provided on each of the individual teeth 118 and aligned in registry when combined in back to back relationship in the teeth assemblies to permit bolts 136 to pass therethrough for mounting purposes thus when the individual teeth 118 are placed back to back and secured together by threaded fasteners such as bolts and nuts or the like they may.