A golf club head comprising a body and a hollow stiffening structure is disclosed herein. The body comprises a face section, a sole section, and a crown section, and defines a hollow interior. The hollow stiffening structure extends within the hollow interior from the crown section to the sole section to reduce stresses placed on the face section during impact with a golf ball. The hollow stiffening structure creates stiffness in a vertical, crown-sole direction of the body, while reducing stiffness in the horizontal, front-rear direction. These two effects combine to increase ball speed and improve other performance metrics from low center through high center ball impact locations, and simultaneously lower CT of the golf club.

A shim or badge is affixed to a golf club body to produce a cap-back iron, giving the appearance of a hollow-body iron. In this way, the golf club can be manufactured with the performance benefits of a game improvement iron, while providing the appearance of a blade, player's iron, and/or a hollow-body iron. For example, by using a lightweight and rigid shim or badge to close a cavity opening and extend into the toe portion in the golf club body, the golf club head can provide increased stiffness in the topline, while lowering CG. Various shim or badge arrangements and materials can be used, and a filler material and/or damper can be included within the cavity to improve sound and feel, while minimizing loss in COR.

Examples of golf club heads and methods to manufacture golf club heads are generally described herein. In one example, a body portion of a golf club head may include a cavity having an opening and an interior structure defined by a wall portion and a base portion. A hosel portion may include an insert portion and a neck portion extending therefrom. The hosel portion may be attached to the body portion by an interference fit between the neck portion and the opening of the cavity. The insert portion may be received inside the cavity and may be spaced apart from the interior structure of the cavity. A space between the insert portion and the interior structure of the cavity may be partially or entirely filled with an adhesive to hold the hosel portion in place. Other examples may be described and claimed.

A golf club head comprising a body and a hollow stiffening structure is disclosed herein. The body comprises a face section, a sole section, and a crown section, and defines a hollow interior. The hollow stiffening structure extends within the hollow interior from the crown section to the sole section to reduce stresses placed on the face section during impact with a golf ball. The hollow stiffening structure creates stiffness in a vertical, crown-sole direction of the body, while reducing stiffness in the horizontal, front-rear direction, and is filled with a weighted dampening insert that extends the entirety of the length of the stiffening structure and blocks entry into the stiffening structure.

A golf club head comprising a body and a hollow stiffening structure is disclosed herein. The body comprises a face section, a sole section, and a crown section, and defines a hollow interior. The hollow stiffening structure extends within the hollow interior from the crown section to the sole section to reduce stresses placed on the face section during impact with a golf ball. The hollow stiffening structure creates stiffness in a vertical, crown-sole direction of the body, while reducing stiffness in the horizontal, front-rear direction. These two effects combine to increase ball speed and improve other performance metrics from low center through high center ball impact locations, and simultaneously lower CT of the golf club.

Disclosed herein is a golf club head that comprises a body. The body comprises a sole portion, a crown portion, a skirt portion, and a face portion, positioned at a forward region of the golf club head, opposite a rearward region of the golf club head, and extending from a toe region to a heel region of the golf club head. At least a portion of the body is made of a titanium alloy. The golf club head also comprises a large weight, coupled to the sole portion of the body and made of a steel alloy. A mass of the large weight is at least 40% of a mass of the portion of the body made of the titanium alloy. A total mass of the large weight and the portion of the body made of the titanium alloy is at least 210 grams.

A golf club head that is capable improving on the inertia properties of a golf club head all while also improving the Center of Gravity (CG) location is disclosed herein. More specifically, the golf club head in accordance with the present invention achieves a relative low Moment of Inertia (MOI) about the Z-axis (MOI-Z) as well as a relatively low MOI about the Shaft-axis (MOI-SA), all combined with a high MOI about the X and Y-axis (MOI-X and MOI-Y) and maintaining a consistently and relatively low CG location measured along a direction tangent to the hosel axis along the X-Y plane (CG-B).

A golf club head including a striking face, a periphery portion surrounding and extending rearwards from the striking face, a damping element including a front surface and a rear surface, the rear surface of the damping element opposite the front surface of the damping element, wherein the striking face comprises a first portion having a substantially constant thickness, wherein the front surface of the damping element comprises a geometric center, wherein the golf club head includes additional damping structures and materials to achieve desired acoustic characteristics.

Embodiments of golf club heads comprising a head interior bounded by a head front portion, a head rear portion, a head heel portion, a head toe portion, a head top portion, and a head sole portion, the golf club heads further comprising various optimized characteristics including optimizing the head center of gravity height and depth in relation to the head volume and mass, are presented herein. Other examples and related methods are also disclosed herein.

A golf club head having localized heat treatment is described herein. Other embodiments are disclosed.