impact. This increases rolling distance and reduces bouncing over the turf. Putters are the only class of club allowed to have certain features, such as two striking faces, non-circular grip cross-sections, bent shafts or hosels, and appendages designed primarily to aid players' aim. Chipper Present in some golfers' bags is the chipper, a club designed to feel like a putter but with a more lofted face, used with a putting motion to lift the ball out of the higher grass of the rough and fringe and drop it on the green, where it will then roll like a putt. This club replaces the use of a high-lofted iron to make the same shot, and allows the player to make the shot from a stance and with a motion nearly identical to a putt, which is more difficult with a lofted iron due to a difference in lie angle. Most chippers have a loft greater than 10 degrees, which is the maximum loft permitted by the Rules of Golf for a club to be classed as a putter, so these clubs are actually classed as irons. To be legal for sanctioned play, a chipper cannot have any feature that is defined in the rules as allowable only on putters, e.g. two striking faces or a flat-topped "putter grip". This disqualifies many chipper designs, but there are some USGA-conforming chippers, and non-conforming designs can still be used for informal play. Construction Overview The shafts of the woods were made of different types of wood before being replaced by hickory in the middle of the 19th century. The varieties of woods included ash, purpleheart, orangewood, and blue mahoe. Despite the strength of hickory, the long-nose club of the mid nineteenth century was still prone to breaking at the top of the back swing. The club heads were often made from woods including apple, pear, dogwood, and beech in the early times until persimmon became the main material. Golf clubs have been improved and the shafts are now made of steel, titanium, other types of metals or carbon fiber. The shaft is a tapered steel tube or a series of stepped steel tubes in telescopic fashion. This has improved the accuracy of golfers. The grips of the clubs are made from leather or rubber. Shaft The shaft is a tapered tube made of metal (usually steel) or carbon fiber composite (referred to as graphite).