Golf Club Head

Abstract

To provide a golf club head providing tolerance of off center hitting, and approaching a centroid to a place where a golf ball may be hit.SOLUTION: A golf club head 100 comprises a centroid 170 which is arranged at an interval of less than 5 mm from a vertical center plane 166 which is vertical to a face surface and extends passing a center of a hitting face. A golf club head 100 further includes a first component having a first melting point and first density, and a second component having a second melting point greater than the first melting point and second density lower than the first density. The second component is configured so that:(i) the second component is at least partially sealed by the first component; (ii) the second component extends to a hosel part below a hosel bore; and (iii) the second component has mass of less than almost 5 g.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This disclosure relates generally to the field of golf clubs. More specifically, it relates to golf club heads with an insert in at least a hosel portion of the club head. [Background technology]

[0002] [Related Applications] This application claims priority to U.S. Provisional Patent Application No. 63 / 032224, the entire contents of which are incorporated herein by reference.

[0003] The goal in golf club head design is to align the center of gravity of the club head with the location on the striking face that is most likely to make contact with the golf ball during the swing, which improves shot accuracy and ensures that as much energy as possible from the golfer's swing is transferred to the golf ball at impact, resulting in a favorable golf shot. DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0004] However, this goal is often difficult to achieve within a given mass budget constraint. This is especially true for "player" iron type golf club heads, where the shape and weight of the heel and hosel sections naturally bias the club head's center of gravity away from the center of the face toward the heel. Golfers who use these club heads also often enjoy a more traditional look, and therefore these golfers may be opposed to design changes that would not only beneficially alter the club head's weight profile, but would also cause the club head to deviate from this traditional look.

[0005] For example, adding weight to the periphery of an iron or wedge-type golf club head can increase the moment of inertia, thereby adding "forgiveness" to off-center hits, but the appearance of such cavity-back club heads can be off-putting to players who prefer the look of blade-type irons and sand wedges.

[0006] Thus, a need exists for a design that discretely shifts weight from one portion of the club head to another to move the center of gravity closer to where the golf ball is likely to be struck, perhaps the center of the face of the club head, while still providing forgiveness on off-center hits. [Means for solving the problem]

[0007] A golf club head according to one or more aspects of the disclosure includes, when oriented in a reference position, a striking face having a face center and defining a face surface, a vertical central plane perpendicular to the face surface and extending through the face center, a sole portion, a top portion, a heel portion, a toe portion opposite the heel portion, and a hosel bore extending from the heel portion and having an open end and a bottom surface for receiving a shaft, the hosel bore including the hosel portion defining a central hosel axis and a center of gravity spaced less than 5 mm from the vertical central plane. The golf club head may also include a first component made of a first material 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 lower than the first density, the second component (i) being at least partially sealed by the first component, (ii) extending into the hosel portion below the hosel bore, and (iii) having a mass of less than about 5 g.

[0008] Also, a method of manufacturing a golf club head according to one or more aspects of the disclosure includes: (a) forming an auxiliary component with an auxiliary material; (b) encapsulating the auxiliary component in a golf club head body including a primary material by a lost wax process; and (c) removing a portion of the auxiliary component to form a hosel bore with an open end and a bottom surface such that a top of the auxiliary component is below the bottom surface. The primary material can have a first melting point and a first density, and the auxiliary material can have a second melting point greater than the first melting point and a second density less than the first density. Also, the golf club head includes a striking face having a face center and defining a face surface, a vertical center plane that is substantially perpendicular to the face surface and passes through the face center, and a center of gravity located less than 5 mm from the vertical center plane.

[0009] Another golf club head according to one or more aspects of the present disclosure may include a golf club head body and an auxiliary component. The golf club head body may include a striking face having a face center and defining a face surface, a vertical center plane perpendicular to the face surface and extending through the face center, a sole portion, a top portion, a heel portion, a toe portion opposite the heel portion, a hosel portion including a hosel bore extending from the heel portion and having an open end and a bottom surface, the hosel bore defining a central hosel axis, and a first material having a first melting point and a first density. The auxiliary component may include a heel portion including a second material having a second melting point higher than the first melting point and a second density lower than the first density, an upper portion located below the bottom surface of the hosel bore, and a toe portion connected to the heel portion and including a third material having a density higher than the first density. The center of gravity of the golf club head may be located less than 5 mm from the vertical central plane. [Brief description of the drawings]

[0010] [Figure 1]1 illustrates a front view of an exemplary golf club head according to one or more aspects of the present disclosure. [Diagram 2] 2 illustrates a rear schematic view of the example golf club head of FIG. 1. [Diagram 3] 1 illustrates a heel side elevation view of an exemplary golf club head according to one or more aspects of the present disclosure. [Figure 4] 4 shows a cross section of the golf club head of FIG. 3 taken along line IV-IV. [Diagram 5] 4 illustrates a front perspective view of the golf club head of FIG. 3 with the hosel removed. [Figure 6] 6 shows a cross-sectional view of the golf club head of FIG. 5 taken along line VI-VI. [Figure 7] 4 illustrates an exemplary method for manufacturing the golf club head of FIG. 3. [Figure 8] 4 shows an enlarged view of an insert within the golf club head of FIG. 3. [Figure 9] 9 shows overlapping club heads as part of a method for designing the insert of FIG. 8. [Figure 10] 8 shows a golf club head resulting from a second step of the method of FIG. 7. [Figure 11] 8 shows a golf club head resulting from a third step of the method of FIG. 7. [Figure 12] 8 illustrates a golf club head resulting from a fourth step of the method of FIG. 7. [Figure 13] 1 illustrates an exemplary method for manufacturing a golf club head according to one or more aspects of the present disclosure. [Figure 14] 14 illustrates a golf club head resulting from a fourth step of the method of FIG. 13. [Figure 15] 1 illustrates a rear cross-sectional view of a golf club head according to one or more aspects of the present disclosure. [Figure 16] 16 shows a heel side cross-sectional view of the golf club head of FIG. 15. [Figure 17] 16 shows a schematic rear view of the golf club head of FIG. 15. [Figure 18]18 shows a cross section of the golf club head of FIG. 17 taken along line XVIII-XVIII. [Figure 19] 18 shows a cross section of the golf club head of FIG. 17 taken along line XIX-XIX. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] These and other features and advantages of the golf club head and method of manufacture thereof according to various aspects of the present disclosure will become more apparent upon consideration of the following description, drawings, and appended claims. The description and drawings set forth below are for illustrative purposes only and are not intended to limit the scope of the present invention in any manner.

[0012] 1 and 2 is a golf club head 100 according to one or more aspects of the present disclosure. The body of the golf club head may be bounded by a toe portion 110, a heel portion 120 opposite the toe portion, a top portion 130, and a sole portion 140 opposite the top portion. A hosel portion 150 for securing the club head to an associated shaft (not shown) may extend from the heel portion and may define an imaginary central hosel axis 152.

[0013] The club head may further include a striking face 160 at its front. The striking face is a front substantially planar exterior portion that substantially coincides with an imaginary face surface and is positioned to contact a golf ball at a factory-specified loft angle obtained between the face surface and the central hosel axis. The striking face may be formed with surface features to increase traction between the striking face and a struck golf ball, ensure good contact with the ball (e.g., in wet conditions), and impart some spin to the ball, for example, for stability during flight or to better control the resting position of the struck golf ball after it returns to the ground due to backspin.

[0014] These surface features may include a plurality of substantially parallel horizontal grooves or scorelines 162, as well as other surface features (not shown) that form a texture pattern. The striking face may include a face center 164. As used herein, face center refers to a point on the striking face of the club head that is midway between the heel-closest and toe-closest portions of the scoreline 162, and midway between the top-closest and sole-closest portions of the scoreline. In golf club heads where the scorelines extend to the toe edge of the striking face, the toe-closest portions of the scorelines are defined by an imaginary vertical plane that extends through the apex of the top of the golf club head.

[0015] An imaginary vertical center plane 166 perpendicular to the face surface projects through the center of the face in the front-to-rear direction of the club head, and a center of gravity 170 of the golf club head may be spaced from the imaginary vertical center plane. In FIG. 1, for example, the center of gravity is spaced from the imaginary vertical center plane in a heel direction. The center of gravity may be spaced from the imaginary vertical center plane by a distance 172 that is less than 5 mm, and in a more preferred embodiment, it may be spaced from the imaginary vertical center plane by less than 2 mm.

[0016] A golf club head is shown in Figure 1 as being in a "reference position." As used herein, "reference position" refers to a position of a golf club head, such as the club head of Figure 1, in which the sole portion of the club head is in contact with an imaginary ground surface 10, the imaginary central hosel axis 152 of the hosel portion is in an imaginary vertical hosel plane, and the scorelines 162 are oriented horizontally relative to the ground surface. Unless otherwise specified, all club head dimensions described herein are taken with the club head in the reference position.

[0017] 1 and 2 preferably includes an iron-type club head, such as a wedge-type club head, which may preferably have a loft angle of 40° or greater. More preferably, the golf club head may be a traditional blade-type club head, or what may otherwise be referred to by certain golfers as a "player" type club head.

[0018] As such, as shown in FIG. 2, the rear portion 180 of the club head may include a top blade portion 182 and a lower muscle portion 184. The top blade portion may preferably include a substantially planar surface, and therefore, it may preferably lack a perimeter weighting feature. The muscle portion may protrude rearward from the top blade portion. The mass of the golf club head may generally be concentrated in the muscle portion, so that the center of gravity 170 may be located on the sole side of the face center. And, as shown in FIG. 2, specifically, the moment of inertia ("MOI") Izz 186 of the golf club head may be measured about an imaginary vertical axis 187 that passes through the center of gravity, and the MOI Ixx 188 of the golf club head may be measured about an imaginary horizontal axis 189 that also passes through the center of gravity and is parallel to the ground. As known to those skilled in the art, the MOI generally correlates to increasing the club head's natural resistance to rotation about a particular axis on off-center golf ball strikes.

[0019] A golf club head according to one or more embodiments of the present disclosure preferably has an internal structure that, compared to other "player" type golf club heads, moves weight from the heel or lower hosel section to the sole / muscle section or upper part of the hosel section, which moves the center of gravity closer to the center of the face, i.e., where an experienced golfer is more likely to strike the golf ball with the striking face, and accordingly increases both the vertical (Izz) and horizontal (Ixx) MOI. Exemplary golf club heads having such internal structures are described below. Each of these exemplary club heads can include the body structure described above in connection with FIGS. 1 and 2.

[0020] Figure 4 illustrates a cross-section of a golf club head according to one embodiment of the disclosure taken along line IV-IV of Figure 3. As shown, a hosel portion 150 of the club head can include a hosel bore 154 that extends from an open top end 156 of the hosel portion to a depth 155 into the hosel portion. The bore can have an upper inner diameter 157 and a lower inner diameter 158, which can be the same or different.

[0021] The hosel bore then terminates at its bottom in a metal shelf 159 that projects inwardly toward an imaginary central hosel axis. The sidewalls of the hosel portion (and the remainder of the golf club head body) are preferably made of steel and / or a tensile strength of 8 g / cm 3 The first component may be formed of a primary material, such as a material having a density equal to or greater than 1500° C. and / or a melting point less than 1600° C. Additionally, the minimum thickness 151 of the sidewall (perimeter wall) of the hosel portion, measured at the bottom of the hosel bore, is preferably sufficient to ensure the structural integrity of the hosel portion without adversely affecting the vibration feedback of the golf shot. For example, this minimum thickness may be 0.5 mm or greater, more preferably 0.75 mm or greater.

[0022] At the bottom, sole side of the hosel bore, may be an insert 190 that functions as a secondary, or supplemental, component. The insert may include a substantially cylindrical portion 192 (FIG. 8) having a central axis that is coaxial with an imaginary central hosel axis. The insert may also include a heel portion shaped to generally match the heel contour of the golf club head.

[0023] The insert may be formed of a complementary material, such as a ceramic, and may preferably have a melting point higher than that of the first component and a density lower than that of the first component. As such, the insert may have a mass of less than about 5 g within the golf club head, and the mass of the insert may be less than about 1.5% of the total mass of the golf club head. The insert may be at least 60% aluminum oxide (Al 2 O 3 More specifically, the ceramic insert may be made of 20% SiO 2 , 10% ZrO 2 , and 70% Al 2 O 3 although these percentages may vary by up to about 10% each.

[0024] By adjusting the ceramic composition, the material properties of the insert can be adjusted to achieve weight distribution goals, such as an increased moment of inertia, a lower and / or more central center of gravity location, or a particular vibration frequency upon impact. The insert may also have the following properties: (i) a bond strength of 15 MPa, (ii) a porosity of 40% or less, preferably 30%, (iii) an adsorption of 30%, (iv) a melting point of greater than 2500°C, and (v) a mass of 3 g / cm. 3 Less than 2 g / cm 3 Density as follows: However, the bond strength, porosity, absorbency and density of the insert, as well as the composition of the insert, may be varied to achieve a particular weight distribution goal.

[0025] As shown in FIG. 6, which shows a cross section taken along line VI-VI in FIG. 5, the insert 190 can extend from the hosel portion to the heel portion of the golf club head. The insert can also affect various MOI values ​​of the golf club head. For example, the vertical MOI Izz can be 3000 g cm 2 The horizontal MOI Ixx can exceed 1000g cm 2 It may be possible to exceed this.

[0026] 7-12 show an exemplary method 200 for forming the golf club head of FIGS. 3-6. In a first step 210, an insert may be formed, for example, by injection molding. FIG. 8 shows one embodiment of an insert 190 after this first molding step. The insert is preferably designed by overlaying various club lofts in a computer-aided design ("CAD") program and selecting overlapping areas of those club heads while considering necessary constraints such as minimum steel wall (perimeter wall) thickness for hosel and / or heel integrity. For example, FIG. 9 shows inserts formed in overlapping areas of club heads having lofts of 46°, 54°, and 64°. This design process may alleviate manufacturing concerns and provide various cost benefits since a new insert does not have to be designed for each golf club head loft and sole shape. In one or more embodiments, the minimum steel wall thickness is 0.5 mm or greater, and more preferably 0.75 mm or greater.

[0027] 7, the golf club head body may then be formed around the insert 190, for example by lost wax casting, and the insert sealed therein. The result of this step is shown in FIG. 10, where the insert is shown to extend through the hosel bore and beyond the opening at the top end 156 of the hosel portion 150, as well as below the metal shelf 159 at the bottom of the hosel bore.

[0028] Next, the upper portion 194 of the insert, i.e., the portion that extends beyond the top opening of the hosel portion and into the hosel bore, may be removed in a third step 230 shown in FIG. 7, for example by machining. As shown in FIG. 11, which shows the result of this third step, the hosel bore 154 and the top end 156 of the hosel portion may now be opened to receive a golf club shaft. The insert 190 may extend to the sole side of the metal shelf 159 that bounds the bottom of the hosel bore. As also shown in FIG. 11, the insert does not extend beyond the heel-most portion 163 of the scorelines formed in the striking face. Preferably, the insert may extend to approximately the heel-most portion of those scorelines. This ensures that the insert does not extend into the striking zone of the striking face, which may minimize changes to the traditional feel and sound of the golf club head upon impact with a golf ball.

[0029] Then, in the final step 240 of FIG. 7, the result of which is shown in FIG. 12, an insert cap 196 may be introduced into the hosel bore so that it rests on the metal shelf 159. This insert cap may be formed of Al or ABS plastic and can provide a protective barrier between the tip of the shaft and the top end of the insert. In other embodiments, when the tip of the shaft is fixed in the hosel bore, an insert cap may not be necessary because the top end of the insert is covered with an epoxy layer. By forming the golf club head body around the insert in this manner, the space that would otherwise be filled with a denser metal material is instead occupied by, for example, a ceramic material. Thus, mass is selectively removed from the hosel and heel portions, thereby achieving the goal of moving the center of gravity closer to the face center.

[0030] Other exemplary club heads are considered to be within the spirit and scope of the present invention. For example, as shown in FIG. 13, similar to the method of FIG. 7, an insert 390 may first be formed in a first step 310, for example, by injection molding. The body of the golf club head may then be formed around the insert in a second step 320, for example, by lost wax casting. However, instead of removing only the top of the insert to form the hosel bore of the hosel portion in a third step 330, more of the insert may be removed to form an internal cavity below the hosel bore. More specifically, as shown in FIG. 14, a portion 392, for example, at least 50% by volume, or all of the insert, may be removed to form the internal cavity, for example, by mechanical agitation, chemical etching, or electrolytic etching. In some embodiments, the insert may be composed of a material that has high solubility in water or an aqueous solution. In such embodiments, the insert may be easily dissolved from the golf club head to form the cavity. This cavity may then be filled in a fourth step 340 of FIG. 13 by injecting a material therein, such as a polymeric foam, which then hardens.

[0031] This fourth step may thus allow for adjustment of the center of gravity location by introducing vibration dampening material into the club head or, for example, by varying the density of a polymeric material. And, as in the method of Figure 7, the insert cap may then be introduced into the hosel bore in a fifth step 350 such that it rests on the metal ledge that bounds the bottom of the hosel bore.

[0032] Still other exemplary club heads are contemplated to be within the spirit and scope of the present invention. For example, although Figures 10-12 and 14 show the insert extending only to the heel-most portion of the scoreline, this need not be the case. Rather, as shown in the exemplary golf club head 400 of Figures 15-19, the insert 490 can extend further into the sole or toe portion of the golf club head.

[0033] The insert may actually extend the entire distance from heel to toe. Such a configuration may be more feasible in "game improving" type golf club heads, which generally have a larger sole volume to accommodate such an insert. Golfers using "game improving" club heads may also find the change in sound and / or feel due to the insert extending into the striking face less objectionable. In fact, the presence of the insert may provide a vibration dampening effect and improve the feel on off-center hits.

[0034] Also, as shown in Figure 19, which shows a cross section of the golf club head of Figure 17 taken along line XIX-XIX, a high density portion 492 may be co-molded with the insert in the toe area or disposed within the insert. This high density portion may be a metallic material, such as a tungsten alloy, which has a modulus of 10 g / cm 3 The inclusion of such a high density portion in the insert can be beneficial as it can add mass to the toe of the golf club head, potentially increasing the MOI, improving the feel of the golf club head when striking a golf ball, and ultimately reducing manufacturing costs.

[0035] In the foregoing discussion, the present invention has been described with reference to certain exemplary embodiments thereof. However, it will be apparent that various modifications and changes can be made to these exemplary embodiments without departing from the broader spirit and scope of the present invention. Accordingly, the foregoing discussion and accompanying drawings should be regarded as merely illustrative of the present invention, rather than limiting its scope in any manner. [Explanation of symbols]

[0036] 100, 400 Golf club head 110 Toe 120 Heel 130 Top Section 140 Sole 150 Hosel part 152 central hosel axis 154 hosel bore 160 hitting face 162 Scoreline 164 Face Center 166 Vertical center plane 170 Center of gravity 192 Cylindrical Section

Claims

1. A golf club head, when oriented in a reference position, a striking face having a face center and defining a face surface; a vertical center plane perpendicular to the face surface and extending through the face center; A sole portion, The top part and A heel portion, a toe portion opposite the heel portion; a hosel portion including a hosel bore extending from the heel portion and having an open end and a bottom surface for receiving a shaft, the hosel bore defining a central hosel axis; a center of gravity spaced less than 5 mm from said vertical central plane; the golf club head includes a first component made of a first material 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 lower than the first density; The second component comprises: (i) at least partially sealed by the first component; (ii) extending into the hosel portion below the hosel bore; and (iii) has a mass of less than about 5 g; the second component further includes a substantially cylindrical portion defining a second central axis coaxial with the central hosel axis; the striking face includes a plurality of horizontally extending scorelines; the second component extends in a heel-toe direction to approximately the portion of the scoreline closest to the heel; Golf club head.

2. 2. The golf club head of claim 1, wherein the first component substantially entirely encloses the second component and defines a minimum perimeter wall thickness that is greater than or equal to 0.5 mm.

3. 3. The golf club head of claim 2, wherein said minimum peripheral wall thickness is greater than or equal to 0.75 mm.

4. The golf club head further has a total mass. The golf club head of claim 1 , wherein the mass of the second component is less than 1.5% of the total mass of the golf club head.

5. The golf club head of claim 1 , wherein the second component has a porosity of 40% or less.

6. an opposing rear surface of the striking face that is substantially flat along a heel-to-toe direction from a portion of the golf club head closest to the heel to a portion of the golf club head closest to the toe; 3000g cm ２ 2. The golf club head of claim 1, further comprising a moment of inertia Izz about a vertical axis passing through the center of gravity that is greater than Izz.

7. 1000g cm ２ The golf club head of claim 6 , further comprising a larger moment of inertia Ixx about a horizontal axis passing through the center of gravity.

8. The golf club head of claim 1 further comprising a cap in communication with said bottom surface of said hosel bore.

9. A golf club head, which, when oriented in a reference position, a striking face having a face center and defining a face surface; a vertical center plane perpendicular to the face surface and extending through the face center; A sole portion, The top part and A heel portion, a toe portion opposite the heel portion; a hosel portion including a hosel bore extending from the heel portion and having an open end and a bottom surface for receiving a shaft, the hosel bore defining a central hosel axis; a center of gravity spaced less than 5 mm from said vertical central plane; the golf club head includes a first component made of a first material 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 lower than the first density; The second component comprises: (i) at least partially sealed by the first component; (ii) extending into the hosel portion below the hosel bore; and (iii) has a mass of less than about 5 g; the golf club head further comprises a rear surface opposite the striking face that is substantially flat along a heel-to-toe direction from a portion of the golf club head closest to a heel to a portion of the golf club head closest to a toe; a moment of inertia Izz about a vertical axis passing through said center of gravity greater than 3000 g·cm 2 , and a moment of inertia Ixx about a horizontal axis passing through said center of gravity greater than 1000 g·cm 2 . Golf club head.

10. A golf club head, which, when oriented in a reference position, a striking face having a face center and defining a face surface; a vertical center plane perpendicular to the face surface and extending through the face center; A sole portion, The top part and A heel portion, a toe portion opposite the heel portion; a hosel portion including a hosel bore extending from the heel portion and having an open end and a bottom surface for receiving a shaft, the hosel bore defining a central hosel axis; a cap communicating with the bottom surface of the hosel bore; a center of gravity spaced less than 5 mm from said vertical central plane; the golf club head includes a first component made of a first material 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 lower than the first density; The second component comprises: (i) at least partially sealed by the first component; (ii) extending into the hosel portion below the hosel bore; and (iii) has a mass of less than about 5 g; Golf club head.

11. 1. A method of forming a golf club head, comprising: forming a supplemental component from a supplemental material; encapsulating the auxiliary components within a golf club head body containing a primary material by a lost wax process; removing a portion of the auxiliary component to create a hosel bore having an open end and a bottom surface, such that a top of the auxiliary component is below the bottom surface; the primary material has a first melting point and a first density, and the secondary material has a second melting point greater than the first melting point and a second density less than the first density; The golf club head includes: a striking face having a face center and defining a face surface; a vertical center plane that is substantially perpendicular to the face surface and passes through the face center; and a center of gravity located less than 5 mm from said vertical central plane. A method for forming a golf club head.

12. The method of claim 11 , wherein the step of forming the auxiliary component comprises an injection molding process.

13. 12. The method of claim 11, wherein the minimum perimeter wall thickness enclosing the auxiliary component is 0.5 mm or greater.

14. 14. The method of forming a golf club head of claim 13, wherein said minimum perimeter wall thickness enclosing said auxiliary component is 0.75 mm or greater.

15. 12. The method of forming a golf club head of claim 11, wherein the mass of the auxiliary component is less than 1.5% of the overall mass of the golf club head.

16. The method of forming a golf club head according to claim 11 , wherein the auxiliary component comprises 40% or less porosity.

17. a rear surface opposite the striking face, the rear surface being substantially flat along a heel-to-toe direction from a portion of the golf club head closest to a heel to a portion of the golf club head closest to a toe; 3000g cm ２ 12. The method of forming a golf club head of claim 11, further comprising a moment of inertia Izz about a vertical axis passing through said center of gravity that is greater than Izz.

18. 1000g cm ２ 20. The method of forming a golf club head of claim 17, further comprising a greater moment of inertia Ixx about a horizontal axis passing through the center of gravity.

19. 12. The method of forming a golf club head of claim 11, further comprising the step of inserting a cap into said bottom surface of said hosel bore.

20. forming an internal cavity by removing at least 50% of the volume of the auxiliary component by a process selected from the group consisting of mechanical agitation, chemical etching, and electrolytic etching; 12. The method of forming a golf club head of claim 11, further comprising the step of: injecting a polymeric material into said internal cavity.

21. A golf club head, when oriented in a reference position, (A) a golf club head body, a striking face having a face center and defining a face surface; a vertical center plane perpendicular to the face surface and extending through the face center; Sole part, Top section, Heel part, a toe portion opposite the heel portion; a hosel portion including a hosel bore extending from the heel portion and having an open end and a bottom surface, the hosel bore defining a central hosel axis; the golf club head body including a first material having a first melting point and a first density; (B) a center of gravity spaced less than 5 mm from said vertical central plane; (C) an auxiliary component, a heel portion including a second material having a second melting point higher than the first melting point and a second density lower than the first density; an upper portion of the second material located below the bottom surface of the hosel bore; and the auxiliary component including a toe portion connected to the heel portion and including a third material having a density greater than the first density; A golf club head including:

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