Abstract: A drill is secured in percussion drilling machines and in tool holders of hammer drills by locking elements. The locking elements fit into axially extending grooves formed in the axially extending circumferential surface of the shank of the drill. Webs located intermediate the ends of the grooves divide the grooves into axially extending groove sections with the locking elements fitting into the groove sections. The outer surfaces of the webs are located in the circumferential surface of the shank and serve to support the jaws of the tool holder in the correct position.

Abstract: A rock drill includes a drill shank with a boring head at one end and laterally enclosed for at least a portion of its length by a tubular shell. A helix extends around the outside of the tubular shell for carrying borings away from the boring head. Supporting members formed of a sound attenuating material are located between the helix and the other parts of the rock drill.