Abstract: A hollow sleeve is mounted in a hole of a holder block to receive a rotary cutter bit. The sleeve includes a front flange and a shank extending rearwardly from the front flange and defining a longitudinal axis. The shank includes an outer periphery having a radially stepped configuration, wherein an outer surface of the shank includes a plurality of axially adjacent surface sections that become successively smaller in cross-section in a direction away from the flange. Each surface section occupies one-third of the hole length. Each surface section has longitudinally spaced front and rear ends, wherein a portion of each surface section situated between its front and rear ends is spaced farther from the axis than are the front and rear ends. Each surface section has a generally longitudinally extending groove formed therein.

Abstract: A hollow sleeve is mounted in a hole of a holder block to receive a rotary cutter bit. The sleeve includes a front flange and a shank extending rearwardly from the front flange and defining a longitudinal axis. The shank includes an outer periphery having a radially stepped configuration, wherein an outer surface of the shank includes a plurality of axially adjacent surface sections that become successively smaller in cross-section in a direction away from the flange. Each surface section occupies one-third of the hole length. Each surface section has longitudinally spaced front and rear ends, wherein a portion of each surface section situated between its front and rear ends is spaced farther from the axis than are the front and rear ends. Each surface section has a generally longitudinally extending groove formed therein.

Abstract: A holder block is mounted on a carrier and has formed therein a first hole and a water passage. A sleeve is mounted in the first hole and receives a cutter bit. The sleeve includes a shank and an enlarged flange disposed at a front end thereof. The shank is disposed in the first hole. The flange includes a rearwardly facing shoulder bearing against an outer surface of the block. A second hole extends through the shank and the flange and is adapted to receive the cutter bit. A spray nozzle is disposed in the flange and is connected to the water passage by way of an annular groove, for receiving water which it sprays forwardly against the cutter bit.