Wood (golf) - Design

Design

The head of a wood is roughly spherical in shape with a slightly bulging clubface and a generally flattened sole that slides over the ground without digging in during the swing. Traditional "wood" clubheads were made of wood, hence the name; beech wood or ash were common prior to the twentieth century, and later persimmon or maple became preferable. Modern club heads are usually hollow steel, titanium or composite materials, and are sometimes called "metalwoods" or more recently "fairway metals". Pinseeker Golf Corp. innovated the first stainless steel metalwood called the Bombshell in 1976. The design was somewhat untraditional and did not have the promotional success needed for profitable long term marketing - it was discontinued 3 years later. In 1979 Taylor Made produced a traditionally shaped stainless steel wood head called "Pittsburgh Persimmon" which achieved market acceptance by the mid-1980s. Oversized heads made from aluminum appeared in the mid-1980s but were slow to catch on since their introduction was via independent component manufacturers and not the larger endorsement based club manufacturers. Very large size drivers (300-500cc) arrived with titanium metallurgy which meant reasonable 'headweights' could be achieved with very large thin shelled but strong structures. By the mid-2000s, titanium heads could be made to 1000 cc (Golfsmith Inc made 1,000 cc (61.0 cu in) in the mid-2000s). Around this time the USGA decided to limit the size of driver heads to 460 cc (28.1 cu in) since the rule requiring heads to be of a traditional shape was being unduly stretched. However, during this period the club-making business needed some financial help, so the USGA relaxed the "traditional shape" rule while enforcing the new 460cc limit, and new head shapes appeared, such as "torpedo" and square/rectangular shapes, to attract the buying public to potentially game improving designs particularly regarding better mishit outcomes.

The typical loft for woods ranges from 7.5 to 31 degrees. Driver lofts generally center around 10.5° but the desired loft is very dependent upon the player's swing speed (low swing speeds need higher lofts); men's lofts vary between 8 and 11 degrees while women's drivers are between 10 and 13 degrees, and seniors' lofts trend toward the upper range by gender. The average 3-wood has a 13-16 degree loft (typically 15°) and the average 5-wood has an 18-21 degree loft. Higher lofts than that overlap with irons in distance, but many players prefer high-number woods to low-number irons wherever they can be used as the wood is easier to hit than a "long iron". The loft of any given club number varies between manufacturers, model lines, and the target player.

The shaft length in woods varies from about 40–48 inches (101.6–121.9 cm), with the current standard length for the driver being 45 in (114.3 cm), formerly 43.5 in (110.5 cm). Graphite shafts are usually preferred for woods due to their light weight, which enables users to generate higher clubhead speeds and thus greater distance. The maximum legal length of a shaft by USGA and R&A rules is 48 in (121.9 cm), though some woods used in long drive contests have been made with shaft lengths up to 50 in (127.0 cm) long.

The face of woods is slightly bulged to counteract the gear effect when the ball hits the face off center. The gear effect causes the ball to spin from hits that are away from the center of the face. The spin contributes a tendency for the ball to have a curved flight path away from the target. The slight bulge of the wood club face tends to counteract the gear effect by slightly changing the direction of the ball to make the flight path of the ball end up closer to the target.