5. Club Face

a. General

The face of the club must be hard and rigid and must not impart significantly more or less spin to the ball than a standard steel face (some exceptions may be made for putters). Except for such markings listed below, the club face must be smooth and must not have any degree of concavity.

b. Impact Area Roughness and Material

Except for markings specified in the following paragraphs, the surface roughness within the area where impact is intended (the “impact area”) must not exceed that of decorative sandblasting, or of fine milling (see Fig. 46). The whole of the impact area must be of the same material (exceptions may be made for clubheads made of wood).

c. Impact Area Markings

If a club has grooves and/or punch marks in the impact area they must  meet the following specifications:

(i) Grooves

(ii) Punch Marks

Note 1: The groove and punch mark specifications above indicated by an asterisk (*) apply only to new models of clubs manufactured on or after 1 January 2010 and any club where the face markings have been purposely altered, for example, by re-grooving. For further information on the status of clubs available before 1 January 2010, refer to the ‘‘Equipment Search’’ section of www.randa.org or “Club and Ball Lists” section of www.usga.org.

Note 2: The Committee may require, through a Model Local Rule, that the clubs the player carries must conform to the groove and punch mark specifications above indicated by an asterisk (*). This Local Rule is recommended only for competitions involving expert players. For further information, refer to the Committee Procedures, Section 8, Model Local Rule G-2 in The Official Guide to the Rules of Golf.

d. Decorative Markings

The centre of the impact area may be indicated by a design within the boundary of a square whose sides are 0.375 inches (9.53 mm) in length. Such a design must not unduly influence the movement of the ball. Decorative markings are permitted outside the impact area.

e. Non-metallic Club Face Markings

The above specifications do not apply to clubheads made of wood on which the impact area of the face is of a material of hardness less than the hardness of metal and whose loft angle is 24 degrees or less, but markings which could unduly influence the movement of the ball are prohibited.

f. Putter Face

Any markings on the face of a putter must not have sharp edges or raised lips. The specifications with regard to roughness, material and markings in the impact area do not apply.