US Patent 10561908 Golf club head

A golf club head including a face portion having an improved restitution factor is provided. The golf club head has a hollow structure and includes a face portion, a crown portion, a sole portion, and a side portion. The crown portion includes a first region that spreads out forward of a boundary line that extends from a heel side to a toe side, and a second region that spreads out rearward of the boundary line and is thinner than the first region. The crown portion further includes a protruding portion formed at position that is in a vicinity of the boundary line, is on the second region, and is rearward of the boundary line via a gap.