Steel vs. Graphite

It's no secret that high modulus graphite has become the preferred shaft material for drivers and fairway woods. More than 90% of all drivers on the PGA tour are shafted with graphite. Why? Because lightweight graphite shafts provide club designers the freedom to create bigger, more forgiving club-heads with larger sweet spots. And, lightweight composites enable golfers to generate more clubhead speed while providing a smoother, solid feel at impact. 

The combination of the lighter shaft and the new head designs generate greater distance.

The vast majority of Touring Pros use steel shafts in their irons to ensure accuracy and control. 

Why? Because steel shafts are more consistent than graphite, providing superior control. Additionally, steel provides greater torsional stability. Robot tests confirm that steel shafts reduce club-head twist at impact resulting in a more controlled ball flight with increased accuracy and tighter shot dispersion

Most shaft selection guides are developed based on center hit data. Their basic assumption are that every stroke results in a dead center hit. 

However, knowing most golfers have swing variations ranging from open/close face to outside-in/inside-out swing path, it is strongly recommend that the degree of variations in your swing is taken into consideration in making your shaft selection. Generally speaking, the greater the swing variations, the lower the torque, the stiffer the shaft flex, and sometimes the heavier the shaft weight should be. 

The lighter the shaft weight, the more active the shaft will be. Therefore, everything being equal, on center hit a lighter shaft will give you longer distance over a heavier shaft. A more active shaft will behave like a high compression golf ball. On center hit it will go farther, and on off-center hit it will be off more. Therefore, the lighter the shaft weight you choose, the lower the torque you should consider.

Properties of a Shaft

Flex refers to the degree of flexibility exhibited by a golf shaft. The dynamic forces of the golf swing cause a shaft to flex and twist in a variety of directions during the swing. Each shaft is engineered to flex and twist in specific locations and to specific degrees when swung at specific swing speeds; for the player to be able to easily square the clubface at impact, the characteristics of the shaft must match the player's swing characteristics. 

Thus different shafts are designed for different players. A shaft designed to flex and twist according to the force generated by a player with a fast swing speed will not behave the same way in the hands of a slower swinger, and vice-versa. In general, stiffer shafts, which are less flexible, work better for faster swingers, and softer, more flexible shafts work better for slower swingers. 

Modern shafts are designed with a variety of flexes and flex characteristics to offer a wide variety of players the optimum level of performance. It's vital that a player's shaft flex be correct, otherwise it will be difficult for him to swing normally and square the clubface. If the shaft is too stiff, the clubface will tend to be open through impact, resulting in shots that fly to the right; if the shaft is too soft, the clubface will tend to be closed through impact, resulting in shots that fly to the left. 

A flex point is also known as the kick point or bend point, where shaft bend is greatest as it is swung.

A shaft with a lower kick point will make the club feel more “tip flexible” and may help you hit the ball just a little higher. A higher kick point shaft will feel stiffer and might cause you to hit shots just a little lower. If you have trouble hitting the ball too high, try a high kick point shaft. If, on the other hand, you hit the ball too low, a lower kick point shaft might help cure your problem. 

In all actuality, the difference between the measured bend points on the highest bend point shafts to the lowest bend point shafts is less than 2 inches. 

Look to kick point more for a feel difference and to head design and club loft for noticeable trajectory difference though.

The amount that a shaft resists twisting when you swing it is the shaft’s torque. Imagine holding the shaft at either end and twisting it. If it could be twisted a great amount, it would have a higher torque. If it were difficult to twist, it would have less torque. 

Torque is measured in degrees; higher degrees of torque mean the shaft will twist more as you swing. 

Proper torque helps to make sure the club is directed toward the target at impact. If you swing fast, you will need a shaft with less torque since your strength lets you get the club aligned toward the target consistently. But, if you swing slower, a shaft that twists more (one that has more torque) can actually help the club face square toward the target for straighter shots. Of course, other factors such as clubhead size, weight and center of gravity also dictate what type of torque a player should use.

Shafts are available in weights ranging from over 125 grams to under 50 grams. Although  graphite shafts are lighter than steel shafts in general, there are actually some steel shafts that are lighter than graphite. 

The weight of a shaft has a significant effect on how the club is swung. If a club is too heavy for a golfer, it cannot be swung at the optimum speed, resulting in a potential distance loss. A shaft that is too heavy will also make it harder to square the club face at impact, resulting in less accurate shots. 

A good rule of thumb is to find the lightest shaft that a player can control; such a shaft will help to maintain swing balance which will allow the player hit the ball longer and more consistently.