US Patent 7651412 Golf club head with progressive face stiffness

A metal wood golf club head adapted for attachment to a shaft, with a body comprising of a first body portion and a second body portion, each portion constructed of a different density material. Combining a high density material in the first body portion with a low density material in the second body portion, creates an ultra-low center of gravity relative to the geometric face center, resulting in higher launch angles and spin rate ratios. Thickening the lower area of the front face lowers the center of gravity and upwardly shifts the coefficient of restitution to the geometric center of the face.