A golf club head according to the present invention is provided with a face portion, a crown portion and a sole portion, the crown portion including a first area extending in a toe-heel direction along at least part of the face portion and a second area arranged further to a back side than the first area, a sloped surface that extends in the toe-heel direction and slopes downward approaching the back side being formed between the first area and the second area, and a transfer sheet that is formed in a shape corresponding to the sloped surface and is a different color from the first area and the second area being stuck to the sloped surface.

A golf club head according to the present invention is provided with a face portion, a crown portion and a sole portion, the crown portion including a first area extending in a toe-heel direction along at least part of the face portion and a second area arranged further to a back side than the first area, a sloped surface that extends in the toe-heel direction and slopes downward approaching the back side being formed between the first area and the second area, and a transfer sheet that is formed in a shape corresponding to the sloped surface and is a different color from the first area and the second area being stuck to the sloped surface.

A method of forming a golf club head, including placing a first portion of the golf club head adjacent a the second portion of the golf club head; welding the first portion to the second portion forming a first weld bead; injecting hot melt into an interior of the golf club head through an injection hole after forming the first weld bead; and welding the injection hole shut, forming a second weld bead.

A method of forming a golf club head, including placing a first portion of the golf club head adjacent a the second portion of the golf club head; welding the first portion to the second portion forming a first weld bead; injecting hot melt into an interior of the golf club head through an injection hole after forming the first weld bead; and welding the injection hole shut, forming a second weld bead.

The present invention is directed to a set of golf clubs comprising long irons, mid irons and short irons. The irons have a progressive horizontal CG location. Preferably, the long and mid irons have a face stabilizing bar and back panel and the CG is located between about 1 mm and 3 mm towards the hosel and the CG in the short irons is located between about 3 mm and 4 mm toward the hosel. Further the long and mid irons irons can have a plurality of apertures in the face stabilizing bar and/or the back wall.

Methods of bifurcating the material properties of golf club heads, and wedges in particular, are disclosed herein. The methods of the present invention preserve the bendability and feel of certain parts of the club heads, such as hosel regions, while selectively hardening and increasing the durability of other features, such as scorelines and texturing on the face.

A method for manufacturing a golf club head includes providing a club head body produced by electric smelting an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities. A solid solution treatment is proceeded at 1020-1080 C. for 80-100 minutes to form austenite and martensite in the club head body. A deep cooling treatment is proceeded between 120 C. and 80 C. for 7-9 hours to turn the austenite in the club head body into martensite. An aging treatment is proceeded on the club head body at 460-500 C. for 210-270 minutes to provide a hardness of HRC 36-46. A hosel is heated with high frequency waves at 900-1000 C. to posses a hardness lower than HRC 20.

A method for manufacturing a golf club head includes providing a club head body produced by electric smelting an alloy base material including 0.04-0.07 wt % of carbon, 0.5-1.0 wt % of manganese, 0.5-1.0 wt % of silicon, less than 0.04 wt % of phosphorus, less than 0.03 wt % of sulfur, 15-17.7 wt % of chromium, 3.6-5.1 wt % of nickel, 2.8-3.5 wt % of copper, with the rest being iron and inevitable impurities. A solid solution treatment is proceeded at 1020-1080 C. for 80-100 minutes to form austenite and martensite in the club head body. A deep cooling treatment is proceeded between 120 C. and 80 C. for 7-9 hours to turn the austenite in the club head body into martensite. An aging treatment is proceeded on the club head body at 460-500 C. for 210-270 minutes to provide a hardness of HRC 36-46. A hosel is heated with high frequency waves at 900-1000 C. to posses a hardness lower than HRC 20.

A method of manufacturing an iron type golf club head, including forming an iron type golf club head blank, the iron type golf club head blank having an oversized hosel portion and an oversized body portion, the iron type golf club head blank configured to accommodate a plurality of iron type golf club heads, each iron type golf club head having a unique loft angle; and removing material from said oversized body portion of said iron type golf club head blank.

A method of manufacturing an iron type golf club head, including forming an iron type golf club head blank, the iron type golf club head blank having an oversized hosel portion and an oversized body portion, the iron type golf club head blank configured to accommodate a plurality of iron type golf club heads, each iron type golf club head having a unique loft angle; and removing material from said oversized body portion of said iron type golf club head blank.