Patent ID: 6095266
Filing Date: 2000-08-01
Classification: B23K,C22C,E21B

Abstract:
A drill rod component adapted to be friction welded to a steel bit to form the drill rod for percussive rock drilling, the component being formed of steel and including a central passage extending therethrough, the component including a first end defining a striking surface, a thread portion disposed adjacent the striking surface, a clearance portion disposed adjacent the thread portion, and a short rod portion disposed adjacent the clearance portion and being of greater diameter than the clearance portion, the short rod portion having a free end adapted to be friction welded to the bit; the thread portion, clearance portion and central passage being nitrocarburized and having a core hardness of at least 390 HV1; the striking surface being high frequency surface hardened to at least 600 HV1; portions of said first and second components disposed on immediate sides of the weld having a hardness of at least 390 HV1.