Abstract: This invention provides a golf club head including a plurality of score lines on the face. The golf club head includes a plurality of striations formed on the face and extending from a toe side to a heel side. The cross-sectional shape of each of the striations is a triangle asymmetric with regard to a virtual center line in the width direction, and the smallest interior angle among three interior angles of the triangle is placed at the sole side of the golf club head. A depth D from the face to the deepest portion of each of the striation satisfies 10 ?m?D?40 ?m.

Abstract: The present invention provides a golf club head comprising, a face, a plurality of score line grooves formed in the face, traces formed in the face by milling; and a pair of side surfaces of the score line groove including a first surface that is contiguous with the face and a second surface that is contiguous with the first surface in the depth direction of the score line groove. A first angle that is formed by each first surface of the pair of side surfaces is larger than a second angle that is formed by each second surface of the pair of surfaces. The face in which the traces are formed has the arithmetic mean deviation of the profile (Ra) of not less than 4.00 ?m.

Abstract: A golf head club has a high moment of inertia and thus produces a pleasing hitting sound. A metallic golf club head 1 having a hollow space therein includes a face member 30 provided with a face part 31, and a body member 10 provided with a sole part 11, a crown part 12, a side part 13, and ribs 20. The hollow space is defined by the inner surfaces of the face part 31, the sole part 11, the crown part 12, and the side part 13, and the wall surfaces of the ribs. The ribs 20 extend from the inner surface of the sole part 11 to the inner surface of the crown part 12, and the body member 10 is molded integrally by casting.

Abstract: A golf club head of this invention includes a face, a plurality of score line grooves formed on the face, and a plurality of striations formed on the face. The angle formed by an arrangement direction of the plurality of striations and the score line grooves is between 40 degrees and 70 degrees, inclusive, as viewed clockwise from a toe side end of the score line grooves.

Abstract: This invention provides a golf club head comprising a plurality of score lines formed in its face. Letting ? be the angle of the side wall of the scoreline with respect to the face, Cp be the center point of a virtual circle which has a radius of 0.254 mm and is inscribed in both the side wall and the face, F be the point of contact between the virtual circle and the face, G be the point of contact between the virtual circle and the side wall, P be a point farthest from the center point Cp in the segment from the point of contact F to the point of contact G in the edge portion of the scoreline, and D (mm) be the length from the center point Cp to the point P, the golf club head satisfies 56°???80° and 0.270?D?0.287.

Abstract: According to this invention, there is provided a method of manufacturing a golf cub head having a plurality of score lines on the face. The method of this invention includes the first forming step of forming grooves for the score lines on the face, and the second forming step of forming flat surfaces inclined with respect to the face by cutting into the edges of the grooves formed in the first forming step.

Abstract: This invention provides a golf club head having a groove formed on a face of the golf club head. Each of a pair of side surfaces of the groove has a first surface leading to the face and a second surface leading to the first surface in the depth direction of the groove. A first angle between the first surfaces of each of the pair of the side surfaces is larger than a second angle between the second surfaces of each of the pair of the side surfaces.

Abstract: A golf club head of a hollow wood type, that includes: a face portion; a body portion including a crown portion; and a film provided on the face portion and at least a front part of the crown portion. A film thickness T1 of the face portion is greater than or equal to a film thickness T2 of the body portion.

Abstract: This invention provides a golf club head including a plurality of score lines on the face. In the golf club head according to this invention, the score line includes a pair of side surfaces and a bottom portion having a protruding portion protruding toward the face. An angle between the side surface and the face is not less than 60 degrees. A cross-sectional area A (inch2) of the score line, a width W (inch) of the score line measured based on the 30 degrees measurement method, and a distance S (inch) between the score lines adjacent to one another satisfy A/(W+S)?0.003.

Abstract: A golf club head of this invention includes a head body, a weight member attached to the head body, and a fixing unit to fix the weight member at one of a plurality of attachment positions of the head body. The plurality of attachment positions are located on a virtual cylindrical surface having the axis of a shaft to be mounted to the golf club head as a center.

Abstract: A golf club head having a hollow construction produces a characteristic low ball hitting sound to accommodate the diversity of golfers' preferences for ball hitting sounds even if the volume of the golf club head is increased to 430 to 500 cc and the weight thereof is decreased to 160 to 220 g. In a golf club head having a hollow construction and including a face part, a sole part, a crown part, and a side part, in which the head volume is 430 to 500 cc, and the head weight is 160 to 220 g, the area of the sole part is increased so that the primary natural frequency of the sole part is 2400 Hz or less, and a weight is formed at a position of the center of vibration in the sole part on the inner surface on the hollow construction side of the sole part.

Abstract: A golf club head of this invention includes a head body, a weight member attached to the head body, and a fixing unit to fix the weight member at one of a plurality of attachment positions of the head body. The plurality of attachment positions are located on a plane. The plane includes the center-of-gravity position of the head body without the weight member attached thereto and the axis of a shaft to be attached to the golf club head.

Abstract: This invention provides a golf club head including a plurality of score lines on the face. The golf club head includes a plurality of striations formed on the face and extending from a toe side to a heel side. A depth Dp of each striation satisfies 10 ?m?Dp?40 ?m. A cross-sectional shape of each striation is an isosceles trapezoid having an upper base at the face side and a lower base at the back side of the golf club head. The upper base and lower base satisfy the upper base>the lower base. A width Pb of the bottom portion of each protrusion formed between the striations and a width Wb of the lower base satisfy Pb<Wb.

Abstract: This invention provides a plurality of grooves formed on a face of the golf club head. Each of a pair of side surfaces of each of the grooves has a first surface leading to the face and a second surface leading to the first surface in the depth direction of the groove. A first angle between the first surfaces of each of said pair of the side surfaces is larger than a second angle between the second surfaces of each of the said pair of the side surfaces. Edges of the groove are rounded. A width W (mm) of the groove measured including the rounded edges, a width Ws (mm) between the grooves adjacent one another, a width Wr (mm) of the groove measured based on the 30 degrees measurement rule and a cross section area S (mm2) of the groove satisfy the following expressions; W/Ws×100?40(%), S/(Ws×0.5)×100?70(%).

Abstract: This invention provides a hollow golf club head having a first viscoelastic body made of a first viscoelastic material and a second viscoelastic body made of a second viscoelastic material with a loss coefficient the temperature dependence of which is different from that of a loss coefficient of the first viscoelastic material.

Abstract: A golf club head of this invention includes a head body, a weight member attached to the head body, and a fixing unit to fix the weight member at any one of a plurality of attachment positions of the head body. The plurality of attachment positions are located on a straight line included in a plane. The plane includes the center-of-gravity position of the head body without the weight member attached thereto and is perpendicular to the toe-and-heel direction of the head body.

Abstract: A golf club head of this invention includes a face and a plurality of striations formed on the face by milling. A pitch P in the arrangement direction of the plurality of striations satisfies 300 ?m?P?600 ?m. The surface roughness of a region in the face with the striations satisfies in the maximum height of the profile Ry, 15 ?m?Ry?0.005×P+15.7 ?m.

Abstract: A golf club head of this invention includes a face, a plurality of score line grooves formed on the face, and traces formed in the face by milling. Edges of the score line grooves are rounded with a radius of not more than 0.2 mm. A width W (mm) of the score line groove measured with the rounded edge being included, a width Ws (mm) between the score line grooves adjacent to one another, a width Wr (mm) of the score line groove measured based on the 30 degrees measurement rule and a cross section area S (mm2) of the score line grooves satisfy the flowing expressions; W/Ws×100?35(%) and S/(Wr×0.5)×100?70(%). The face in which the traces are formed has the arithmetic mean deviation of the profile (Ra) of not less than 4.00 ?m.

Abstract: A golf club head according to the present invention comprises a plurality of score lines on a face, and a stair-shaped portion comprising a plurality of steps formed on a side wall of the score line from a face side end of the side wall in a depth direction of the score line.

Abstract: There is provided a golf club head that produces a loud hitting sound satisfying the golfer even if the volume of the golf club head having a hollow structure is increased to at least about 400 cc. A golf club head 1 having a hollow structure comprises a face part 2, a side part 3 comprising a back side, a sole part 4, a crown part 5, and a hosel part 9 having a shaft insertion hole, and the crown part 5. The crown part comprises a thick region 6 and a thin region 8. The thick region 6 extends through a distance WA of at least about 20 mm from the center axis line C of the shaft insertion hole toward the highest point T of the crown part 5 and extends through a distance WB of at least about 30 mm from the center axis line C of the shaft insertion hole toward the back side so that the crown part 5 has the first-order natural frequency of at least about 3000 Hz.