Appendix II - Design of Clubs

Any design in a club or ball which is not covered by Rules 4 and 5 and Appendices II and III, or which might significantly change the nature of the game, will be ruled on by the R&A.;
The dimensions contained in Appendices II and III are referenced in imperial measurements. A metric conversion is also referenced for information, calculated using a conversion rate of 1 inch = 25.4 mm. In the event of any dispute over the conformity of a club or ball, the imperial measurement takes precedence.

A player in doubt as to the conformity of a club should consult the R&A.;
A manufacturer should submit to the R&A; a sample of a club, which is to be manufactured for a ruling as to whether the club conforms with the Rules. If a manufacturer fails to submit a sample or to await a ruling before manufacturing and/or marketing the club, the manufacturer assumes the risk of a ruling that the club does not conform with the Rules. Any sample submitted to the R&A; becomes its property for reference purposes.

The following paragraphs prescribe general regulations for the design of clubs, together with specifications and interpretations. Further information relating to these regulations and their proper interpretation is provided in 'A Guide to the Rules on Clubs and Balls'.
Where a club, or part of a club, is required to have some specific property, this means that it must be designed and manufactured with the intention of having that property. The finished club or part must have that property within manufacturing tolerances appropriate to the material used.

1. Clubs
a. General
A club is an implement designed to be used for striking the ball and generally comes in three forms: woods, irons and putters distinguished by shape and intended use. A putter is a club with a loft not exceeding ten degrees designed primarily for use on the putting green.
The club must not be substantially different from the traditional and customary form and make. The club must be composed of a shaft and a head. All parts of the club must be fixed so that the club is one unit, and it must have no external attachments except as otherwise permitted by the Rules.

b. Adjustability
Woods and irons must not be designed to be adjustable except for weight. Putters may be designed to be adjustable for weight and some other forms of adjustability are also permitted. All methods of adjustment permitted by the Rules require that:

(i) the adjustment cannot be readily made;
(ii) all adjustable parts are firmly fixed and there is no reasonable likelihood of them working loose during a round; and
(iii) all configurations of adjustment conform with the Rules.

The disqualification penalty for purposely changing the playing characteristics of a club during a stipulated round (Rule 4-2a) applies to all clubs including a putter.

c. Length
The overall length of the club must be at least 18 inches (457.2 mm) and, except for putters, must not exceed 48 inches (1,219.2 mm). For woods and irons, the measurement of length is taken when the club is lying on a horizontal plane and the sole is set against a 60 degree plane as shown in Fig. I. The length is defined as the distance from the point of the intersection between the two planes to the top of the grip. For putters, the measurement of length is taken from the top of the grip along the axis of the shaft or a straight line extension of it to the sole of the club.

Note: Clubs in breach of the maximum length limit as specified in Appendix II, 1c, which were in use or marketed prior to 1st January 2004 and which otherwise conform to the Rules, may be used until 31st December 2004.

d. Alignment
When the club is in its normal address position the shaft must be so aligned that:

(i) the projection of the straight part of the shaft on to the vertical plane through the toe and heel must diverge from the vertical by at least 10 degrees;
(ii) the projection of the straight part of the shaft on to the vertical plane along the intended line of play must not diverge from the vertical by more than 20 degrees forwards or 10 degrees backwards.

Except for putters, all of the heel portion of the club must lie within 0.625 inches (15.88 mm) of the plane containing the axis of the straight part of the shaft and the intended (horizontal) line of play.

2. Shaft
a. Straightness
The shaft must be straight from the top of the grip to a point not more than 5 inches (127 mm) above the sole, measured from the point where the shaft ceases to be straight along the axis of the bent part of the shaft and the neck and/or socket.

b. Bending and Twisting Properties
At any point along its length, the shaft must:

(i) bend in such a way that the deflection is the same regardless of how the shaft is rotated about its longitudinal axis; and
(ii) twist the same amount in both directions.

c. Attachment to Clubhead
The shaft must be attached to the clubhead at the heel either directly or through a single plain neck and/or socket. The length from the top of the neck and/or socket to the sole of the club must not exceed 5 inches (127 mm), measured along the axis of, and following any bend in, the neck and/or socket.

Exception for Putters: The shaft or neck or socket of a putter may be fixed at any point in the head.

3. Grip
The grip consists of material added to the shaft to enable the player to obtain a firm hold. The grip must be straight and plain in form, must extend to the end of the shaft and must not be moulded for any part of the hands. If no material is added, that portion of the shaft designed to be held by the player must be considered the grip.

(i) For clubs other than putters the grip must be circular in cross-section, except that a continuous, straight, slightly raised rib may be incorporated along the full length of the grip, and a slightly indented spiral is permitted on a wrapped grip or a replica of one.
(ii) A putter grip may have a non-circular cross-section, provided the cross-section has no concavity, is symmetrical and remains generally similar through-out the length of the grip. (See Clause (v) overleaf).
(iii) The grip may be tapered but must not have any bulge or waist. Its cross-sectional dimensions measured in any direction must not exceed 1.75 inches (44.45 mm).
(iv) For clubs other than putters the axis of the grip must coincide with the axis of the shaft.
(v) A putter may have two grips provided each is circular in cross-section, the axis of each coincides with the axis of the shaft, and they are separated by at least 1.5 inches (38.1 mm).
4. Clubhead
a. Plain in Shape
The clubhead must be generally plain in shape. All parts must be rigid, structural in nature and functional. It is not practicable to define plain in shape precisely and comprehensively but features which are deemed to be in breach of this requirement and are therefore not permitted include:

(i) holes through the head,
(ii) transparent material added for other than decorative or structural purposes,
(iii) appendages to the main body of the head such as knobs, plates, rods or fins, for the purpose of meeting dimensional specifications, for aiming or for any other purpose. Exceptions may be made for putters.

Any furrows in or runners on the sole must not extend into the face.

b. Dimensions and Size
(i) Woods
When the club is in a 60 degree lie angle, the dimensions of the clubhead must be such that:

(a) the distance from the heel to the toe of the clubhead is greater than the distance from the face to the back;
(b) the distance from the heel to the toe of the clubhead is not greater than 5 inches (127 mm); and
(c) the distance from the sole to the crown of the clubhead is not greater than 2.8 inches (71.12 mm).

These dimensions are measured on horizontal lines between vertical projections of the outermost points of:

• the heel and the toe; and
• the face and the back;

and on vertical lines between the horizontal projections of the outermost points of the sole and the crown. If the outermost point of the heel is not clearly defined, it is deemed to be 0.875 inches (22.23 mm) above the horizontal plane on which the club is lying.

The size of the clubhead must not exceed 28.06 cubic inches (460 cubic centimetres), plus a tolerance of 0.61 cubic inches (10 cubic centimetres).

Note: Clubs in breach of the maximum size limit as specified in Appendix II, 4b (i), which were in use or marketed prior to 1st January 2004 and which otherwise conform to the Rules, may be used until 31st December 2004.

(ii) Irons and Putters
When the clubhead is in its normal address position the dimensions of the head must be such that the distance from the heel to the toe is greater than the distance from the face to the back. For traditionally shaped heads, these dimensions will be measured on horizontal lines between vertical projections of the outermost points of:

• the heel and the toe; and
• the face and the back.

For unusually shaped heads, the toe to heel dimension may be made at the face.
c. Striking Faces
The clubhead must have only one striking face, except that a putter may have two such faces if their characteristics are the same, and they are opposite each other.

5. Club Face
a. General
The material and construction of, or any treatment to, the face or clubhead must not have the effect at impact of a spring (test on file), or impart significantly more or less spin to the ball than a standard steel face, or have any other effect which would unduly influence the movement of the ball.
The face of the club must be hard and rigid (some exceptions may be made for putters) and, except for such markings listed below, 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.
The whole of the impact area must be of the same material. Exceptions may be made for wooden clubs.

c. Impact Area Markings
Markings in the impact area must not have sharp edges or raised lips as determined by a finger test. Grooves or punch marks in the impact area must meet the following specifications:

(i) Grooves. A series of straight grooves with diverging sides and a symmetrical cross-section may be used.

• The width and cross-section must be consistent across the face of the club and along the length of the grooves.
• Any rounding of groove edges must be in the form of a radius which does not exceed 0.020 inches (0.508 mm).
• The width of the grooves must not exceed 0.035 inches (0.9 mm), using the 30 degree method of measurement on file with the R&A.;
• The distance between edges of adjacent grooves must not be less than three times the width of a groove, and not less than 0.075 inches (1.905 mm).
• The depth of a groove must not exceed 0.020 inches (0.508 mm).
  
  

(ii) Punch Marks. Punch marks may be used.

• The area of any such mark must not exceed 0.0044 square inches (2.84 sq. mm).
• A mark must not be closer to an adjacent mark than 0.168 inches (4.27 mm) measured from centre to centre.
• The depth of a punch mark must not exceed 0.040 inches (1.02 mm).
• If punch marks are used in combination with grooves, a punch mark must not be closer to a groove than 0.168 inches (4.27 mm), measured from centre to centre.

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 apply to clubs on which the impact area of the face is of metal or a material of similar hardness. They do not apply to clubs with faces made of other materials and whose loft angle is 24 degrees or less, but markings which could unduly influence the movement of the ball are prohibited. Clubs with this type of face and a loft angle exceeding 24 degrees may have grooves of maximum width 0.040 inches (1.02 mm) and maximum depth 1.5 times the groove width, but must otherwise conform to the markings specifications above.

f. Putter Face Markings
The specifications above with regard to roughness, material and markings in the impact area do not apply to putters.