IRON TYPE GOLF CLUB HEAD
A head 2 includes a face surface 4, a back surface 6, and a sole surface 8. The back surface 6 includes a top side region Rt and a sole side region Rs. The sole side region Rs includes a sole side inclination surface Sb 1 inclined to increase a face thickness toward a sole side, a plurality of back recessed parts Rb 1 formed on the sole side inclination surface Sb 1, and a wall WL 1 formed between the back recessed parts Rb 1 adjacent to each other. A low specific gravity member X 1 having a specific gravity lower than the specific gravity of the face material is disposed on at least one of the back recessed parts Rb 1. The head 2 has a loft angle of equal to or greater than 42°. The head 2 has a sweet spot height of equal to or greater than 19 mm.
1 . An iron type golf club head comprising a face surface formed by a face material, a back surface, and a sole surface extending between the face surface and the back surface, wherein
the back surface includes a top side region and a sole side region positioned between the top side region and the sole surface,
the sole side region includes a sole side inclination surface inclined to increase a face thickness toward a sole side, a plurality of back recessed parts formed on the sole side inclination surface, and at least one wall formed between the back recessed parts adjacent to each other,
a low specific gravity member having a specific gravity lower than a specific gravity of the face material is disposed on at least one of the back recessed parts,
the golf club head has a loft angle of equal to or greater than 42°, and
the golf club head has a sweet spot height of equal to or greater than 18.5 mm.
2 . The iron type golf club head according to claim 1 , wherein a high specific gravity member having a specific gravity higher than the specific gravity of the face material is disposed on the top side region.
3 . The iron type golf club head according to claim 1 , wherein
the number of the back recessed parts is equal to or greater than 5, and
the number of the walls is equal to or greater than 4.
4 . The iron type golf club head according to claim 1 , wherein the low specific gravity member is not disposed on at least one of the back recessed parts.
5 . The iron type golf club head according to claim 1 , wherein the plurality of back recessed parts are arranged in a toe-heel direction.
6 . The iron type golf club head according to claim 1 , wherein the plurality of back recessed parts include a first back recessed part positioned on a most heel side, a second back recessed part positioned on a most toe side, and a third back recessed part positioned between the first back recessed part and the second back recessed part.
7 . The iron type golf club head according to claim 1 , wherein each of the back recessed parts forms a space between the face surface and the sole surface.
8 . The iron type golf club head according to claim 1 , wherein an inner surface of each back recessed part has a recessed part front surface which is a surface opposite to the face surface.
9 . The iron type golf club head according to claim 1 , wherein the wall extends in a direction perpendicular to the face surface.
10 . The iron type golf club head according to claim 2 , wherein the high specific gravity member has a center of gravity positioned on an upper side with respect to a center of gravity of the head.
11 . The iron type golf club head according to claim 1 , wherein a total volume of the back recessed parts is equal to or greater than 3500 mm 3 but equal to or less than 6000 mm 3 .
12 . The iron type golf club head according to claim 1 , wherein
the plurality of walls are provided, and
an interval of the walls is equal to or greater than 4 mm but equal to or less than 12 mm.
13 . The iron type golf club head according to claim 1 , wherein the wall has a thickness of equal to or greater than 1 mm but equal to or less than 4 mm.
14 . The iron type golf club head according to claim 8 , wherein the low specific gravity member is brought into contact with the recessed part front surface.