Golf club head

A golf club head comprising:

• a heel portion;
• a toe portion;
• a crown;
• a sole;
• and
• a face having a striking surface for striking a golf ball;
• the face having an ideal impact location at a center of the striking surface defining the origin of a coordinate system including an x-axis, extending tangent to the center of the striking surface and generally parallel to a flat ground surface when the golf club head is in an address position on the flat ground surface, a y-axis, extending substantially perpendicular to the x-axis and generally parallel to the flat ground surface when the golf club head is in the address position on the flat ground surface, and a z-axis, extending substantially perpendicular to the x-axis and to the y-axis, wherein a negative direction of the x-axis points toward the heel portion and a positive direction of the x-axis points toward the toe portion;
• the face further having a first off-center location on the face located in a heel direction away from the center of the striking surface at −40 mm along the x-axis and a second off-center location on the face located in a toe direction away from the center of the striking surface at 40 mm along the x-axis;
• wherein a characteristic time at 10 mm increment locations on the face along the x-axis between the first off-center location and the second off-center location deviates from the characteristic time at the center of the striking surface by no more than 20%;
• wherein a moment of inertia about a center-of-gravity (CG) x-axis, passing through a CG of the golf club head and parallel to the x-axis, is between about 300 kg·mm2 and about 500 kg·mm2;
• wherein a moment of inertia about a CG z-axis, passing through the CG of the golf club head and parallel to the z-axis, is between about 450 kg·mm2 and about 650 kg·mm2;
• wherein the golf club head comprises a body, which is made of a metallic material, and an insert made of a non-metal composite material including a face plate comprising a plurality of composite prepreg plies, and a polymer cover layer having a cover layer thickness of 0.2-1.2 mm and defining the striking surface, wherein the insert is attached directly to the body via an adhesive and the polymer cover layer includes a plurality of surface features to provide a mean roughness of 2.5-5 μm;
• wherein the face defines a variable thickness profile, comprising a thickness at the center of the striking surface that is greater than a thickness at a peripheral edge of the striking surface, thereby adjusting the characteristic time at various locations along the x-axis, wherein the thickness at the center of the striking surface is between 4 mm and 9 mm and the thickness at the peripheral edge of the striking surface is between 3 mm and 6 mm;
• and
• the golf club head has a depth of at least 111.76 mm, a CG y-axis coordinate of 30-50 mm, and a CG z-axis coordinate of between about −10 mm and about −2 mm.

A golf club head comprising:

• a heel portion;
• a toe portion;
• a crown;
• a sole;
• a face having a striking surface for striking a golf ball;
• the face having an ideal impact location at a center of the striking surface defining the origin of a coordinate system including an x-axis, extending tangent to the center of the striking surface and generally parallel to a flat ground surface when the golf club head is in an address position on the flat ground surface, a y-axis, extending substantially perpendicular to the x-axis and generally parallel to the flat ground surface when the golf club head is in the address position on the flat ground surface, and a z-axis, extending substantially perpendicular to the x-axis and to the y-axis, wherein a negative direction of the x-axis points toward the heel portion and a positive direction of the x-axis points toward the toe portion;
• the face further having a first off-center location on the face located in a heel direction away from the center of the striking surface at −40 mm along the x-axis and a second off-center location on the face located in a toe direction away from the center of the striking surface at 40 mm along the x-axis;
• and
• a weight port configured to retain a movable weight;
• wherein a characteristic time at 10 mm increment locations on the face along the x-axis between the first off-center location and the second off-center location deviates from the characteristic time at the center of the striking surface by no more than 20%;
• wherein the face defines a variable thickness profile, comprising a thickness at the center of the striking surface that is greater than a thickness at a peripheral edge of the striking surface, thereby adjusting the characteristic time at various locations along the x-axis, wherein the thickness at the center of the striking surface is between 4 mm and 9 mm and the thickness at the peripheral edge of the striking surface is between 3 mm and 6 mm;
• wherein a moment of inertia about a center-of-gravity (CG) x-axis, passing through a CG of the golf club head and parallel to the x-axis, is between about 300 kg·mm2 and about 500 kg·mm2;
• wherein a moment of inertia about a CG z-axis, passing through the CG of the golf club head and parallel to the z-axis, is between about 450 kg·mm2 and about 650 kg·mm2;
• wherein the weight port is located at a back portion of the golf club head, the back portion being on an opposite side of the golf club head as the face;
• wherein the golf club head comprises a body, which is made of a metallic material, and an insert made of a non-metal composite material including a face plate comprising a plurality of composite prepreg plies including a plurality of prepreg panels and at least one cluster comprising a plurality of prepreg strips, and a polymer cover layer having a cover layer thickness of 0.1-3.0 mm and defining the striking surface, wherein the insert is attached directly to the body via an adhesive, and the plurality of composite prepreg plies includes a plurality of prepreg panels and at least one cluster comprising a plurality of overlapping prepreg strips;
• the golf club head has a depth of at least 111.76 mm, a CG y-axis coordinate of 30-50 mm, and a CG z-axis coordinate of between about −10 mm and about −2 mm;
• wherein the golf club head has a volume between 400 cc and 500 cc, and the insert has an insert height dimension of between 50 mm and 127 mm;
• and
• wherein the polymer cover layer includes a plurality of surface features to provide a mean roughness of 2.5-5 μm.