Grooves of golf club heads and methods to manufacture grooves of golf club heads

1. A golf club head comprising:

a non-hollow body having a club face to engage a golf ball; and

at least one groove having a variable depth and extending a length between a first end and a second end of the club face,

wherein the variable depth comprises a first depth associated with a first depth portion and a second depth associated with a second depth portion, the first depth being greater than the second depth, the first depth portion extending from a location between the first end and the center to a location between the second end and the center, the second depth portions having same depths and extending between the first end and the first depth portion and extending between the second end and the first depth portion,

wherein a greatest depth of the at least one groove is between the first end and the second end and is at least partly offset relative to a center of the length,

wherein first depth portion has the same de th as the greatest depth,

wherein the depths of the second depth portions are less than the greatest depth, and

wherein the first depth portion extends less than half of the length of the at least one groove.

2. A non-hollow golf club head as defined in claim 1 , wherein at least a portion of a bottom surface of the groove between the first end and the center is convex relative to the club face and faces away from the first end.

3. A non-hollow golf club head as defined in claim 1 , wherein the greatest depth of the at least one groove is substantially at the center.

4. A golf club head comprising:

a club face to engage a golf ball; and

at least one variable depth groove having a heel end and a toe end defining a length of the groove,

wherein a greatest depth of the at least one groove is between the heel end and the toe end and is at least partly offset relative to a center of the length, is offset relative to the first end and is offset relative to the second end.

5. A golf head as defined in claim 4 , wherein the groove comprises:

a first depth portion extending from a location between the heel end and the center to a location between the toe end and the center;

second depth portions having same depths and extending between the heel end and the first depth portion and extending between the toe end and the first depth portion;

wherein first depth portion has the same depth as the greatest depth; and

wherein the depths of the second depth portions are less than the greatest depth.

6. A golf club head as defined in claim 5 , wherein the groove further comprises third depth portions defining transition portions between the first depth portion and the second depth portions.

7. A golf club head as defined in claim 4 , wherein the groove comprises:

a first depth portion extending from a location between the heel end and the center to a location between the toe end and the center;

second depth portions having same depths and extending between the heel end and the first depth portion and extending between the toe end and the first depth portion;

wherein the depths of the second depth portions are the same as the greatest depth; and

wherein the depth of the first depth portion is less than the greatest depth.

8. A golf club head as defined in claim 7 , wherein the groove further comprises third depth portions defining transition portions between the first depth portion and the second depth portions.

9. A golf club head as defined in claim 4 , wherein the greatest depth is greater than 0.020 inches and less than 0.022 inches.

10. A golf club head as defined in claim 4 , wherein the greatest depth portion is closer to the center than to the heel end or the toe end.

11. A golf club head comprising:

a club face to engage a golf ball;

at least one groove having a heel end and a toe end defining a length of the groove, a center of the groove being defined by a center of the length;

wherein at least a portion of a bottom surface of the groove between the heel end and the center is convex relative to the club face and faces away from the heel end and faces generally toward the toe end, or wherein at least a portion of the bottom surface of the groove between the toe end and the center is convex relative to the club face and faces away from the toe end and faces generally toward the heel end.

12. A golf club head as defined in claim 11 , wherein a greatest depth of the at least one groove is substantially at the center.

13. A golf club head as defined in claim 11 , wherein the groove comprises:

a first depth portion extending from a location between the heel end and the center to a location between the toe end and the center;

second depth portions having same depths and extending between the heel end and the first depth portion and extending between the toe end and the first depth portion;

wherein at least a portion of the first depth portion has the same depth as a greatest depth of the at least one groove; and

wherein the depths of the second depth portions are less than the greatest depth.

14. A golf club head as defined in claim 13 , wherein the groove further comprises third depth portions defining transition portions between the first depth portion and the second depth portions.

15. A golf club head as defined in claim 11 , wherein the groove comprises:

a first depth portion extending from a location between the heel end and the center to a location between the toe end and the center;

second depth portions having same depths and extending between the heel end and the first depth portion and extending between the toe end and the first depth portion;

wherein the depth of at least a portion of each of the second depth portions is the same as a greatest depth of the at least one groove; and

wherein the depth of the first depth portion is less than the greatest depth.

16. A golf club head as defined in claim 15 , wherein the groove further comprises third depth portions defining transition portions between the first depth portion and the second depth portions.

17. A golf club head as defined in claim 11 , wherein a greatest depth of the at least one groove is greater than 0.020 inches and less than 0.022 inches.

18. A golf club head as defined in claim 11 , wherein a greatest depth of the at least one groove is closer to the center than to the heel end or the toe end.

19. A method of forming a club head comprising:

providing a club face to engage a golf ball; and

forming at least one variable depth groove having a heel end and a toe end defining a length of the groove,

wherein a greatest depth of the at least one groove is between heel end and the toe end and is at least partly offset relative to a center of the length, is offset relative to the first end and is offset relative to the second end.

20. The method as defined in claim 19 , wherein forming the at least one variable depth groove comprises forming a depth portion associated with a depth greater than 0.020 inches but less than 0.022 inches.