A guide to understanding shaft vocabulary
Monday, February 20, 2012
PACIFIC PALISADES, Calif. - Golf shafts come with their own vocabulary. Understanding the language of shafts is not always easy.
During a rainy practice day at the Northern Trust Open, Philip Foster and Ben Grusin of Mitsubishi Rayon sat down to discuss the words, expressions and descriptions that help distinguish one golf shaft from another.
Keep in mind that no industry standards exist for torque, flex or frequency. This means one manufacturer’s measurement may be conducted using a different method or scale from another manufacturer.
TORQUE: A measurement of the circular rotation of the shaft during the swing. Normal measurements are in the 2- to 6-degree range. A low torque number means less twisting of the shaft but also can mean a harsher feel. A high torque number is associated with a soft-feeling shaft, although there may be a sacrifice in accuracy.
FLEX: The strength of a shaft as it bends during the swing. Because extra stiff, stiff, regular, seniors and ladies flexes are measured in so many ways, these designations have become broad in nature. Comparing flexes from one shaft manufacturer makes sense, but comparing flexes from several shaft manufacturers can be confusing.
FREQUENCY: A more precise method of measuring shaft strength, although measurements from one frequency machine cannot necessarily be compared to those from another machine. As a shaft vibrates, these machines measure the number of vibrations. The higher the vibration count, the stiffer the shaft.
EI CURVE: A measurement of structural rigidity throughout the shaft. The EI curve shows exactly how the shaft is bending from tip to butt during the swing. Generally it is considered a more reliable measurement than flex or frequency.
KICK POINT: Modern shafts, particularly graphite shafts, can produce kick in different sections of the shaft -- high kick, mid kick and low kick being three obvious points of reference. Fitters often spend considerable time matching a golfer’s swing with a particular kick. A lower kick point produces a higher trajectory, while a higher kick point results in a lower flight pattern.
FERRULE: The ferrule is an oval piece, commonly made of plastic, that is located just above the neck of the clubhead. Modern ferrules not only are decorative, they are made with great precision to provide accurate and secure bonding between the shaft and clubhead.
BUTT: The top end of the shaft, called the butt, is located underneath the grip. Shafts have different amounts of torque and flex in the butt, just as they do in other sections of the shaft.
TIPPING: The tip end of the shaft, which is inserted into the clubhead, sometimes is cut or trimmed to provide more stiffness in the shaft. This is called tipping. While the practice is common on professional tours, it is not widely used among amateur golfers.
TIP CONFIGURATIONS: Tip sizes (.335, .355 or .370, for example) are expressed in thousandths of an inch. The tips on wood shafts are smaller (most are .335), while the tips on irons are larger. Furthermore, tips are either parallel or tapered. Many touring pros believe .355 taper-tip iron shafts provide superior feel.
WEIGHT: Overall shaft weight usually is expressed in grams. This reflects the weight of an uncut shaft. Once a shaft is trimmed, of course, the final weight is reduced. Stronger flexes generally weigh more than regular, senior or ladies flexes of the same model. True Temper's Dynamic Gold, the most popular steel iron shaft on the PGA Tour, weighs abourt 130 grams. At the other end of the spectrum, Mitsubishi Rayon has a Bassara graphite driver shaft that weighs about 35 grams.
RAW: A raw shaft is an uncut shaft that has not been installed in a clubhead.
BLANK: This is another word for a raw shaft. When clubmakers refer to a blank, they mean a raw shaft.
SPINE ALIGNMENT: Golf shafts, because they are round and hollow, have a spine that is a result of the manufacturing process. Spining (or “puring,” as it is called by SST Pure, which holds several patents in this technique) focuses on the alignment of a shaft in a clubhead: The spine is placed in a particular position in relationship to the head, the purpose being to produce optimal results. The effectiveness of spining for ordinary golfers remains somewhat controversial. Many touring pros, in the name of consistency and accuracy, have their clubs adjusted for spine placement. Most amateurs, however, do not.
FITTER: The person who measures and recommends particular shafts for particular clubheads, depending on how an individual swings the club. Fitting can be complex and is often called an art form.
COUNTER-BALANCING: The process of adding weight to the butt end of the club, whether more material is manufactured into the upper end of the shaft or whether it is an add-on that is secured inside the butt of the shaft. Counter-balancing lowers the swingweight of a club, changing the feel as well. Proponents of counter-balancing say it increases swing speed for some golfers.
BALANCE POINT: Closely related to counter-balancing, balance point is sometimes cited as an important element of feel and performance. The more weight in the butt, the higher the balance point. Although it is not a widespread practice, some fitters use balance point as one of the variables in prescribing a shaft.
PAINT: Sure, it’s decorative, but paint is responsible for three to five grams of shaft weight. Unpainted shafts are extremely rare.
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