US Patent 7083531 Iron-type golf club

An iron-type golf club head (20) includes a body (22) having a front wall (28) with a ball-striking surface (40). The body (22) further includes a rear surface (54) that has external rear cavity (56) formed therein. The rear surface (54) includes an upper portion (58) and a lower portion (60). The upper portion (60) is separated from the lower portion (59) by the external rear cavity (56) and at least one groove (64, 66). The lower portion (60) of the rear surface (54) has a notch (62) formed therein, which communicates with the external rear cavity (56). The golf club head (20) preferably has high moments of inertia Izz and Ixx.