Patent ID: 7296641

Claim:
A rock drill bit for percussive drilling comprising a head portion defining a longitudinal center axis and including a front face; the front face including radially outer and inner portions; a plurality of fluid channels disposed in the head portion and communicating with the inner portion of the front face; the inner portion carrying a plurality of front buttons; the outer portion comprising circumferentially spaced steel portions that are axially raised relative to the inner portion, each raised portion carrying at least one but not more than two peripheral buttons located radially outwardly of an imaginary circle which intersects at least two of the front buttons and at least two of the flushing channels; the imaginary circle arranged coaxially relative to the center axis, wherein circumferentially spaced, longitudinally extending peripheral grooves are formed in an outer periphery of the bit, the front face communicating with each peripheral groove by an additional groove which is inclined radially outwardly and axially rearwardly.