US Patent 7410221 Retainer sleeve in a degradation assembly

A degradation assembly has an attack tool with a body and a shank. The body has a wear resistant tip with a hardness of at least 60 HRc. The shank is disposed within a bore of a holder secured to a driving mechanism. A retainer sleeve is disposed around the shank of the attack tool, wherein an annular gap of 0.002 to 0.010 inches exists between at least a portion of the sleeve and the shank.