| CPC A63B 53/0458 (2020.08) [A63B 53/0408 (2020.08); A63B 53/047 (2013.01)] | 19 Claims |

|
1. An iron type golf club comprising:
a golf club head, a grip and a shaft therebetween,
wherein the golf club head is comprised of a striking face portion located at a frontal portion of the golf club head and a body portion comprising a hosel for receiving the shaft, a topline extending across an upper portion of the golf club head, a toe portion, a heel portion and a sole portion at a bottom portion of the golf club head;
the striking face portion has a striking face area and comprises nine zones, including a center zone that surrounds a face center of the striking face portion, an upper center zone located between the center zone and the topline, a lower center zone located between the center zone and the sole portion, a heel center zone located between the center zone and the heel portion, a heel upper zone located between the heel center zone and the topline, a heel lower zone located between the heel center zone and the sole portion, a toe center zone located between the center zone and the toe portion, a toe upper zone located between the toe center zone and the topline, and a toe lower zone located between the toe center zone and the sole portion:
wherein the center zone has a substantially uniform center zone thickness t1 and has a center zone area A1 that is between about 15% and 35% of the striking face area;
wherein the upper center zone has a variable thickness that increases from minimum thickness t1 adjacent to a center zone to a maximum thickness t2 adjacent the topline and has a upper center zone area A2;
wherein the lower center zone has a variable thickness that increases from minimum thickness t1 adjacent to the center zone to a lower center zone maximum thickness t3 adjacent the sole portion and has a lower center zone area A3;
wherein the heel center zone has a variable thickness that increases from minimum thickness t1 adjacent to the center zone to a heel center zone maximum thickness t4 adjacent the heel portion and has a heel center zone area A4;
wherein the heel upper zone has a variable thickness that increases from minimum thickness t1 at a point adjacent to the center zone and heel center zone to a heel upper zone maximum thickness t5 adjacent the topline and has a heel upper zone area A5;
wherein the heel lower zone has a variable thickness that increases from minimum thickness t1 at a point adjacent to the center zone and heel center zone to a heel lower zone maximum thickness t6 adjacent the sole portion and has a heel lower zone area A6;
wherein the toe center zone has a variable thickness that increases from minimum thickness t1 adjacent to the center zone to a toe center zone maximum thickness t7 adjacent the toe portion and has a toe center zone area AZ;
wherein the toe upper zone has a variable thickness that increases from minimum thickness t1 at a point adjacent to the center zone and toe center zone to a toe upper zone maximum thickness t8 adjacent the topline and has a toe upper zone area A8; and
wherein the toe lower zone has a variable thickness that increases from minimum thickness t1 at a point adjacent to the center zone and toe center zone to a toe lower zone maximum thickness t9 adjacent the sole portion and has a toe lower zone area A9; and
wherein the following equation is satisfied:
![]() |