Patent ID: 7614964

Claim:
A hollow golf club head comprising a face portion having a front face defining a clubface and a rear face facing the hollow, the face portion being provided in the rear face with a central protrusion and a plurality of radial protrusions extending radially from the central protrusion towards a peripheral edge of the face portion, whereby, between the radial protrusions, resultant reduced-thickness parts extending radially from the central protrusion towards the peripheral edge of the face portion are formed, wherein the radial protrusions include at least one variable-width radial protrusion having a width increasing towards the peripheral edge from the central protrusion, the central protrusion comprises a main part having a substantially constant thickness of from 2.5 to 4.0 mm, and a thickness-transitional part surrounding the main part, the radial protrusions have a thickness less than the thickness of the main part, the reduced-thickness parts have a minimum thickness of 1.6 to 3.0 mm, and the thickness-transitional part has a thickness decreasing towards the peripheral edge so as to merge with the radial protrusions.