Embodiments of golf club heads and methods to manufacture golf club heads are generally described herein. A golf club head includes a means for defining an interior cavity including a first material having a first density. The golf club head also includes a first means for increasing a moment of inertia of the means for defining the interior cavity, a second means for increasing a moment of inertia of the means for defining the interior cavity, and a third means for increasing a moment of inertia of the means for defining the interior cavity. The first, second, and third means include a second material having a second density greater than the first density. A portion of the first, second, and third means define visible portions of a back wall portion of the means for defining an interior cavity. Other examples and embodiments may be described and claimed.

A golf club includes a golf club head, a shaft adapter secured within a hosel of the golf club head, and a shaft secured within the shaft adapter. The golf club shaft is formed from a fiber reinforced polymer and extends along a longitudinal axis between a tip end and a grip end. The golf club shaft includes a tip end section, a grip end section, and a tapered section between the tip end section and the grip end section. The tapered section of the shaft includes a reference portion within the upper half that has a frustoconical shape with a near-constant taper rate, and a narrowed portion within the lower half. The narrowed portion is recessed relative to a reference surface extrapolated from the frustoconical shape.

A golf club head includes a striking face, virtual striking face plane generally parallel to the striking face, and scorelines. A hosel portion includes a hosel exterior surface and internal bore to receive a golf shaft. At least a portion of a recessed region is located in the hosel exterior surface where the hosel portion meets at least one of a sole portion, rear portion, and top portion. A first virtual vertical plane is perpendicular to the virtual striking face plane and passes through a face center. A second virtual vertical plane is perpendicular to the striking face plane and passes through a heel-most extent of the scorelines, and the recessed region is located heel-ward of the second virtual vertical plane. A center of gravity is spaced from the first virtual vertical plane in a heel-to-toe direction by a distance no greater than 6.0 mm.

A golf club head comprises a body including a top and a bottom and a hosel connected to the body. The body comprises a forward face defining a leading edge and an opposing rearward facing surface defining a trailing edge. At least one weight shifting element is positioned on the rearward facing surface. A sole extends between the leading edge and the trailing edge and defines a center portion, a first end surface and a second end surface. A static bounce angle is equal to an effective bounce angle when the center portion is square with the ground, and the effective bounce angle is greater than the static bounce angle when the center portion is not square with the ground and the second end surface is positioned away from the ground.

Described herein is a tour iron having a golf club head with a faceplate, a body, and an insert. A sole, top rail, rear, and the faceplate enclose a cavity within the body. The cavity can house the insert. The insert can comprise a low-density material, allowing weight to be concentrated around the peripheral edge of the golf club head. The rear of the golf club head has an inflection seam running from the heel to the toe. The golf club head has an upper portion, above the inflection seam and a lower portion below the inflection seam. The lower portion can have a depth greater that the upper portion depth. The faceplate, body, and insert can be formed of different materials having different densities. The golf club head has a comparatively high moment of inertia and a low center of gravity. Other embodiments and methods are described herein.

Embodiments are described herein of a bifurcated heat treatment apparatus and methods for localized heat treatment of a golf club hosel or golf club head. The heat treating method comprises a bifurcated process in which the golf club head is treated in the first heating unit via induction heating and then moved to the second heating unit for convection heating. Both steps are to localize the hosel heat treatment. The heat treatment apparatus may also include a cooling component, such as a heat sink, to ensure the body of the club head remains at the correct temperature during the second heating stage when the hosel is heated in isolation. The overall bifurcated method and apparatus of the localized heat treatment leads to a hosel or golf club head with at least two different hardness values to allow for manipulation of the material without cracking or fracturing.

Embodiments of golf club heads, golf clubs, and methods to manufacture golf club heads and golf clubs are generally described herein. In one example, a golf club head may include a body portion comprising a first material. The body portion may have a toe portion, a heel portion, a top portion, a sole portion, a back portion, a front portion having a face portion. The golf club head may include an interior cavity partially, substantially, or entirely filled with a first filler material and a second filler material. Other examples and embodiments may be described and claimed.

A golf club head includes a center of gravity spaced less than 5 mm from a vertical center plane that is perpendicular to a striking face plane and extends through a striking face center. The golf club head also includes a first component having a first melting point and a first density and a second component having a second melting point higher than the first melting point and a second density less than the first density. And the second component (i) is at least partially encapsulated by the first component, (ii) extends into a hosel portion below a hosel bore, and (iii) has a mass less than about 5 g.

Embodiments of golf club heads and methods to manufacture golf club heads may include a golf club head having a body portion, a first mass portion, and a second mass portion. The first mass portion has a first mass portion first end and a first mass portion second end such that a distance between the first mass portion first end and the first mass portion second end defines a first mass portion dimension. The second mass portion includes a second mass portion first end and a second mass portion second end such that a distance between the second mass portion first end and the second mass portion second end defines a second mass portion dimension. The second mass portion dimension may be substantially greater than the first mass portion dimension, and a total mass of the second mass portion may be greater than or equal to three times a total mass of the first mass portion. Other examples and embodiments may be described and claimed.

Embodiments of a golf club head comprising a body having a body material density, a strike face having a strike face material density, and a coating comprising a coating material having a coating material density greater than the body material density or the strike face material density are described herein.