Drill bit with recessed cutting face

A percussive rock drill bit head provided at one end of an elongate shank having an internal bore extending axially along a longitudinal axis from one end of the shank towards the head, the head comprising:

• an axially forward facing annular crushing face;
• a generally annular gauge collar projecting axially forward from the crushing face at a perimeter of the head and having a gauge face positioned axially forward of the crushing face;
• a central island being axially raised from the crushing face and having a front face positioned axially forward from the crushing face;
• a first and second generally annular shear face extending axially between the crushing face and the gauge face and the crushing face and the front face respectively, wherein the first and second shear faces are inclined at an angle to extend transverse to the longitudinal axis of the shank;
• at least one cutting button provided on each of the crushing, gauge, front and first and second shear faces;
• a plurality of curved flushing grooves in communication with the internal bore and extending radially outward from the island towards and through the gauge collar to separate the gauge collar into collar segments;
• and
• an annular channel being defined between the island and the gauge collar configured to create an annular ridge in the rock and accordingly reduce the rock breaking resistance.