In one aspect of the invention, a degradation assembly has an attack tool with a body and a shank, the body having a wear-resistant tip. The shank is disposed within a bore of a holder secured to a driving mechanism. The bore of the holder comprises an inner surface comprising a hardness greater than...http://www.google.com/patents/US7338135?utm_source=gb-gplus-sharePatent US7338135 - Holder for a degradation assembly
