Engineered residual stress in golf clubs

A method of manufacturing a driver, or other types of golf club, includes inducing residual compressive stress by high intensity laser shock peening to form an array of laser shock peened impact zones on the club face. Laser pulses having irradiance greater than 4 GW/cm2, with spot size greater than 4 mm2 are used, including a pulse with on the order of 16 ns, with spot size greater than 9 mm2. Residual compressive stress of more than 400 MPa penetrating with a depth of more than 0.2 mm are imparted, without increased hardening in or damage to the face of the club. Laser shock peening a pattern that covers an interior area leaves the perimeter unpeened, inducing a stress gradient between interior area and the perimeter of the club face. Multiple layers of arrays of laser shock impact zones are applied on the club. The technology is readily applied to assembled club heads.