Putter-type golf club head
A putter-type golf club head includes a striking face with a plurality of grooves having a variable depth profile and a variable pitch. Groove variation is tailored to correspond to the golf club heads' moment-of-inertia, mass, or another attribute. A surface treatment method includes selecting a variable depth profile and a variable pitch for a plurality of grooves and surface milling a striking face of a golf club head to form the plurality of grooves.
1. A surface treatment method comprising:
surface milling a striking face of a golf club head, using a cutter, thereby forming a plurality of grooves, the striking face comprising a face center,
wherein:
the plurality of grooves comprises a variable depth profile such that groove depth generally decreases from groove to groove in a laterally outward direction of the face center of the striking face; and
the surface milling occurs at a rotational speed and a feed rate such that groove pitch generally increases in a laterally outward direction of the face center.
2. The method of claim 1 , wherein the rotational speed is varied, at least in part, according to a predetermined moment-of-inertial of the golf club head.
3. The method of claim 1 , wherein the feed rate is varied, at least in part, according to a predetermined moment-of-inertia of the golf club head.
4. The method of claim 1 , wherein the depth profile is varied, at least in part, according to a predetermined moment-of-inertia of the golf club head.
5. The method of claim 1 , wherein the plurality of grooves comprises:
a first plurality of arcuate grooves; and
a second plurality of arcuate grooves at least partially intersecting the first plurality of grooves.
6. The method of claim 1 , wherein the groove depth is approximately equal to:
a d x 2 +b d x+c d ,
where a d , b d , and c d are each a predetermined number and x is a horizontal distance from the face center of the striking face.
7. The method of claim 1 , wherein the pitch is approximately equal to:
a p x 2 +b p x+c p ,
where a p , b p , and c p are each a predetermined number and x is a horizontal distance from the face center of the striking face.
8. The method of claim 1 , wherein each of the plurality of grooves has a substantially constant depth along the particular groove.
9. A golf club head that, when oriented in a reference position, comprises:
a top portion,
a bottom portion opposite the top portion;
a heel portion;
a toe portion opposite the heel portion; and
a striking face comprising a face center and a plurality of grooves, each of the plurality of grooves having a substantially constant depth along the particular groove, the plurality of grooves having a variable depth from groove to groove as measured in a heel-to-toe direction,
wherein the plurality of grooves has a pitch approximately equal to:
a p x 2 +b p x+c p ,
where a p ,b p , and c p are each a predetermined number and x is a horizontal distance from an imaginary vertical line intersecting the face center.
10. The golf club head of claim 9 , wherein the plurality of grooves includes a variable pitch as measured in the heel-to-toe direction.
11. The golf club head of claim 9 , wherein the depth of each of the plurality of grooves has a maximum variance of about 10 μm or less.
12. The golf club head of claim 9 , wherein the depth of each of the plurality of grooves has a maximum variance of about 5 μm or less.
13. The golf club head of claim 9 , wherein the depth of the plurality of grooves is approximately equal to:
a d x 2 +b d x+c d ,
where a d , b d , and c d are each a predetermined number and x is a horizontal distance from an imaginary line intersecting the face center.