The swing weight of a golf club specifies how heavy the club feels to a player swinging it. Swing weight relates not only to the club’s weight but also to the distribution of the weight. A club with more of its mass concentrated in the club head has a higher swing weight and requires more energy for the golfer to swing it at a specific speed. Golfers should use clubs with the correct swing weight to maximize their potential.
In the 1920s, club manufacturers invented swing weight as a measure of the dynamic feel of the golf club. The value relates to the moment of inertia of the club at a fulcrum point, near the grip end of the club. Moment of inertia is the resistance of an object to rotation, just as mass is its resistance to linear motion.
Club makers measure swing weight with a special balance that positions the club at the correct fulcrum point and determines the amount of weight required to counterbalance the overhanging portion of the club. The balance may read directly in swing weight, or it may require a chart to convert its readings to swing weight.
Expressing Swing Weights
Swing weights use a letter-and-number combination that represents the range and the specific reading. There are six ranges, from A through F, and each has 10 values, numbered 0 through 9. A0 is the lightest, and F9 is the heaviest. Most men’s clubs fall in the range of C9 to D8, with D2 being the standard, and ladies' clubs are usually between C4 and D0. One point on the scale is equivalent to a weight difference of .07 oz. at the club head, about the weight of a penny. Few players would even notice such a small change.
Stronger players should use higher swing weights, and weaker ones require clubs with lower values. The correct swing weight is one that is light enough for the player to achieve enough club head speed for proper distance and ball flight but heavy enough to transfer sufficient energy to the ball and keep the club on track in the downswing.
Adding or subtracting weight to the club anywhere except at the fulcrum point changes a club’s swing weight. Attaching lead tape or removing material from the club head, using a different weight shaft or changing the grip size all have affect swing weight. The length of the club also has an impact. Changing the shaft length by 1/2 inch or choking down on the club 1/2 inch changes the value by 3 points.