Patent attributes
Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are generally described herein. In one example, a golf club head may include a body portion having an interior cavity and a front portion. A face portion is attached to the front portion of the body portion to enclose the interior cavity. The golf club head may further include a first filler material coupled to a portion of an inner wall of the body portion, and a second filler material between the first filler material and the face portion and coupled to the face portion. The first filler material has a greater coefficient of restitution (COR) than the second filler material, and the second filler material has a greater stiffness than the first filler material. Other examples and embodiments may be described and claimed.