An important variation in different clubs is loft, or the angle between the club's face and the vertical plane. It is loft that makes a golf ball leave the tee on an ascending trajectory, not the angle of swing; virtually all swings contact the ball with a horizontal motion. The impact of the club compresses the ball, while grooves on the clubface give the ball backspin (a clockwise spin when viewed from a parallel standpoint to the left of the ball). Together, the compression and backspin create lift. The majority of woods and irons are labeled with a number; higher numbers indicate shorter shafts and higher lofts, which give the ball a higher and shorter trajectory.
While the variation of clubs can differ greatly between golfers, a set used to play a round of golf must have no more than 14 clubs. A full set typically consists of a driver, two fairway woods (generally 3- and 5-woods), a set of irons from 3 to 9, a pitching wedge, a sand wedge, a putter, and one more club of the player's choice. Many players opt to avoid the 3- and 4-irons (which are more difficult to hit). Another common variation is to use only the 3, 5, 7 and 9 out of the numbered irons. The extra space in the player's bag can then be filled with more woods, easier-to-hit "hybrid" clubs, additional high-loft or intermediate wedges, and/or a specialized chipping club or multiple putters.
Irons are golf clubs with a flat angled face and a shorter shaft than a wood, designed for shots approaching the green or from more difficult lies such as the rough, through or over trees, or the base of hills. As with woods, "irons" get their name because they were originally made from cast iron. High-loft irons are called wedges. The higher the number gets on the scale, the lower amount of angle difference from 90 degrees.
There are usually four types of wedges with lofts ranging from 48° to 60°: pitching wedge (PW 48°), gap wedge (GW 52°), sand wedge (SW 56°), and lob wedge (LW 60°). The pitching wedge is sometimes called or labeled as a 10 iron, and the gap wedge is often called an approach wedge and labeled with AW. Also present in some golfers' bags is the "chipper" or "chipping wedge" which is designed for low-speed swings to lift the ball a short distance (20–30 yards) onto the green. The club if used takes the place of a pitching wedge used with an abbreviated swing to accomplish the same end. Most chippers however have more in common with putter design than that of wedges.
Hybrids are a cross between a wood and an iron, giving these clubs the wood's long distance with the iron's familiar swing. These clubs generally are used instead of either fairway woods or low-numbered irons, though some manufacturers produce entire sets of hybrids or "iron replacements" that incorporate hybrid design to add distance and forgiveness to a player's entire set of irons from 3 or 4 all the way to pitching wedge. These clubs are often referred to as "Rescues" because the TaylorMade Rescue was one of the first clubs to utilize this design, as well as the use of the clubs to get one out of a tricky position (to be in fact rescued by the club).
Putters are a special class of clubs with a loft not exceeding ten degrees, designed primarily to roll the ball along the grass, generally from a point on the putting green towards the cup. Contrary to popular belief, putters do have a loft (often 5 degrees from truly perpendicular at impact) that helps to lift the ball from any indentation it has made. This increases rolling distance and reduces bouncing over the turf.
Prior to 1935, hickory was the dominant material for shaft manufacturing, but it proved difficult to master for most golfers, as well as being quite frail. Steel would become the ubiquitous choice for much of the second half of the twentieth century. Although heavier than hickory, it is much stronger and more consistent in its performance. Prior to steel, a player would need a slightly different swing for each shaft given the inherent inconsistencies in the hickory shafts. The graphite shaft was first introduced in 1973 but did not gain widespread use until the mid 1990's and is now used on almost all woods and some iron sets, as the carbon-fiber composite of graphite shafts boasts increased flex for greater clubhead speed at the cost of slightly reduced accuracy due to greater torque. Steel, which generally has lower torque but less flex than graphite, is still widely preferred by many for irons, wedges and putters as these clubs stress accuracy over distance.
Shafts are quantified in a number of different ways. The most common is the shaft flex. Simply, the shaft flex is the amount that the shaft will bend when placed under a load. A stiffer shaft will not flex as much, which requires more power to bend and "whip" through the ball properly (which results in higher club speed at impact for more distance), while a more flexible shaft will whip with less power required for better distance on slower swings, but may torque and over-flex if swung with too much power causing the head not to be square, resulting in lower accuracy. Most shaft makers offer a variety of flexes. The most common are: L (Lady), A (Soft Regular, Intermediate or Senior), R (Regular), S (Stiff), and X (Tour Stiff, Extra Stiff or Strong). A regular flex shaft is generally appropriate for those with an average head speed (80-94 mph), while an A-Flex (or senior shaft) is for players with a slower swing speed (70-79 mph), and the stiffer shafts, such as S-Flex and X-Flex (Stiff and Extra-Stiff shafts) are reserved only for those players with an above average swinging speed, usually above . Some companies also offer a "stiff-regular" or "firm" flex for players whose club speed falls in the upper range of a Regular shaft (90-100 mph), allowing golfers and clubmakers to fine-tune the flex for a stronger amateur-level player.
On off-center hits, the clubhead twists as a result of a torque, reducing accuracy as the face of the club is not square to the player's stance at impact. In recent years, many manufacturers have produced and marketed many low-torque shafts aimed at reducing the twisting of the clubhead at impact, however these tend to be stiffer along their length as well. Most recently, many brands have introduced stiff-tip shafts. These shafts offer the same flex throughout most of the shaft, in order to attain the "whip" required to propel the ball properly, but also include a stiffer tip, which cuts back drastically on the lateral torque acting on the head.
Widely overlooked as a part of the club, the shaft is considered by many to be the engine of the modern clubhead. Current graphite shafts weigh considerably less than their steel counterparts, allowing for lighter clubs that can be swung at greater speed. Within the last ten years, performance shafts have been integrated into the club making process. Performance shafts are designed to address specific criteria, such as to launch the ball higher or lower or to adjust for the timing of a player's swing to load and unload the shaft at the correct moments of the swing for maximum power. Whereas in the past each club could come with only one shaft, today's clubheads can be fit with dozens of different shafts, creating the potential for a much better fit for the average golfer.
According to the rules of golf, all club grips with the exception of the putter must have a circular cross-section. The putter may have any cross section that is symmetrical along the length of the grip on at least one plane. Grips may taper from thick to thin along their length (and virtually all do), but are not allowed to have any waisting (a thinner section of the grip surrounded by thicker sections above and below it) or bulges (thicker sections of the grip surrounded by thinner sections). Minor variations in surface texture (such as the natural variation of a "wrap"-style grip) are not counted unless significant.
Though materials advances have resulted in more durable, longer-lasting soft grips, grips eventually dry out, harden or are damaged and must be replaced. Replacement grips sold as do-it-yourself kits are generally inexpensive and of high quality, though custom grips that are larger, softer and/or textured differently from the everyday "wrap"-style grip are generally bought and installed by a clubsmith. Regripping previously required toxic, flammable solvents to soften and activate the adhesive, and a vise to hold the club steady while the grip was forced on, but the newest replacement kits use double-sided tape with a water-activated adhesive that is slippery when first activated, allowing easier installation. Once the adhesive cures, it creates a very strong bond between grip and shaft and the grip is usually impossible to remove without cutting it off.
The hosel is the portion of the clubhead to which the shaft attaches. Though largely ignored by players, hosel design is integral to the balance, feel and power of a club. Modern hosels are designed to place as little mass as possible over the top of the striking face of the club, which lowers the center of gravity of the club for better distance.
Other large scale USGA rulings involve a 1990 suit, and subsequent settlement, against Karsten Manufacturing, makers of the PING Brand, for their use of square, or U-grooves in their immensely popular Ping Eye2 iron models. The USGA argued that players who used the Eye2 had an unfair advantage in imparting spin on the ball, which helps to stop the ball on the putting greens. Ping ultimately changed the design of subsequent Eye2s, the older clubs were "grandfathered in" and allowed to remain in play as part of the settlement. Today square grooves are considered perfectly legal under the Rules of Golf.
Showing the typical range of distances in yards achieved by a first class player with each club.
64° is the most loft on a wedge per most association standards