Equipment Rules

This publication contains guidelines to help manufacturers, rules officials and other interested parties interpret the Rules relating to the design and manufacture of golf clubs and balls, as set forth in Appendices II and III of "The Rules of Golf."

Similar to the Rules, these guidelines will be continually reviewed, and modifications may be made in the future. The principles and philosophies expressed within this publication are held by both the United States Golf Association and R&A Rules Limited ("The R&A").

 

 

 

 

 

 

 

Browse the 2012-2015 Rules

Appendix III — The Ball

 

Introduction

Appendix III is divided into the following six categories:

  1. General
  2. Weight
  3. Size
  4. Spherical Symmetry
  5. Initial Velocity
  6. Overall Distance Standard

Prior to 2008, the Rules on the golf ball were precise and numerical in comparison to the more descriptive rules relating to clubs. In 2008, the USGA added general language to the Rules on golf balls to ensure that any new technology which may be developed in the future which might circumvent the intent of the Rules, while generally covered in the preamble to Appendices II and III, was also directly addressed in Appendix III. Other than this general provision, all of the specifications listed below are tested and checked under laboratory conditions. These specifications are discussed briefly below. However, the official test protocols are available on the USGA’s Web site.

1. General

The ball must not be substantially different from the traditional and customary form and make. The material and construction of the ball must not be contrary to the purpose and intent of the Rules.

Along with the specifications listed below, the USGA conducts additional testing and inspections to identify golf balls with unusual material, construction and/or performance characteristics which may be considered substantially different from the traditional and customary form and make and/or contrary to the purpose and intent of the Rules.

2. Weight

Appendix III, 2 states that a ball must not weigh more than 1.620 ounces avoirdupois (45.93 gm). This is one of the simpler tests because all that is required is an accurate scale. There is no minimum weight, thus a ball can be as light as the manufacturer desires.

3. Size

The ball must have a diameter of not less than 1.680 inches (42.67 mm). The instrument used to measure size is a metal ring gauge. It is important to note that there is no maximum size, the ball can be as large as desired provided it conforms to all other standards.

4. Spherical Symmetry

The intent of this rule is simply to ensure that a ball is designed and manufactured to behave symmetrically.

5. Initial Velocity

There is a formal test procedure carried out on equipment approved by the USGA to check that golf balls meet the Initial Velocity specification. The intent of this Rule is to limit the speed of the ball off the clubface.

6. Overall Distance Standard

This Rule was introduced in 1976 in order to restrict the overall distance (carry and roll) that a ball can travel under specific conditions. This test protocol is continuously reviewed to ensure that it reflects the game as played with modern equipment.

 

Partner Links
AmEx image
AmEx image
AmEx image
AmEx image
Chevron
   

The USGA and Chevron have committed to using the game of golf to encourage students in science, technology, engineering and math (STEM) disciplines. This commitment has led to the creation of extensive golf-focused STEM teaching tools, and has resulted in charitable contributions to support golf-related programs through Eagles for Education™

At U.S. Open Championships the Chevron STEM ZONE™ is an interactive experience highlighting the science and math behind the game of golf through a variety of hands-on exhibits and experiments.

The partnership has also produced educational materials such as the Science of Golf video series and a nationally-distributed newspaper insert which are provided to teachers as tools to enhance existing curriculum in schools. These lessons teach the science behind the USGA’s equipment testing, handicapping, and agronomy efforts.

For more interactive experiences featuring golf-focused STEM lessons, visit the partnership homepage.

Chevron image
Rolex
   

Rolex has been a longtime supporter of the USGA and salutes the sportsmanship and great traditions unique to the game. This support includes the Rules of Golf where Rolex has partnered with the USGA to ensure golfers understand and appreciate the game.

As the official timekeeper of the USGA and its championships, they also provide clocks throughout host sites for spectator convenience.

For more information on Rolex and their celebration of the game, visit the Rolex and Golf homepage.



Rolex image
IBM
   

IBM has partnered with the USGA to bring the same technology, expertise, and innovation it provides to businesses all over the world to the USGA and golf's national championship.

IBM provides the information technology to develop and host the U.S. Open’s official website, www.usopen.com, as well as the mobile apps and scoring systems for the three U.S. Open championships. These real-time technology solutions provide an enhanced experience for fans following the championship onsite and online.

For more information on IBM and the technology that powers the U.S. Open and businesses worldwide, visit http://www.usopen.com/IBM

AmEx image
Lexus
   

Lexus is committed to partnering with the USGA to deliver a best-in-class experience for the world’s best golfers by providing a fleet of courtesy luxury vehicles for all USGA Championships.

At each U.S. Open, Women’s Open and Senior Open, Lexus provides spectators with access to unique experiences ranging from the opportunity to have a picture taken with both the U.S. Open and U.S. Women’s Open trophies to autograph signings with legendary Lexus Golf Ambassadors in the Lexus Performance Drive Pavilion.

For more information on Lexus, visit http://www.lexus.com/

AmEx image
American Express
   

Together, American Express and the USGA have been providing world-class service to golf fans since 2006. By creating interactive U.S. Open experiences both onsite and online, American Express enhances the USGA’s effort to make the game more accessible and enjoyable for fans.

For more information on American Express visit www.americanexpress.com/entertainment


AmEx image