Golf club heads

A putter-type golf club head, comprising:

• a body having a ball striking face member made of a material having a first hardness characteristic;
• wherein a cavity defined in the body at a location behind the ball striking face member;
• wherein a plurality of independent and separated openings are defined in the ball striking face member, the independent and separated openings extending rearward from the ball striking face member at a non-perpendicular angle with respect to the ball striking face member so as to open into the cavity, and wherein at least some of the independent and separated openings extend across a central portion of the ball striking face member;
• a polymeric material provided to at least partially fill the plurality of openings and the cavity;
• wherein the polymeric material has a second hardness characteristic that is softer than the first hardness characteristic, and wherein the material making up the ball striking face member between adjacent openings and the polymeric material exposed in at least some of the openings extend across the central portion of the ball striking face member and provide a ball striking surface of the body that contacts a ball when struck by the putter-type golf club head;
• wherein a plurality of grooves are defined in the ball striking face member, wherein the plurality of grooves extend across the central portion of the ball striking face member and are formed in at least one of:
• (a) the material making up the ball striking face member between adjacent openings and (b) the polymeric material exposed in the openings in the ball striking face member;
• wherein at least one of the grooves has a first edge that constitutes the material making up the ball striking face member, and a second edge opposite the first edge, that constitutes the polymeric material.