Golf shafts have many technical specifications that you, as an average golfer, likely never consider. You are indirectly aware of them because they affect how your clubs feel when you swing them. But those specs affect how your club performs, and club fitters take them into account when they fit you for new clubs. Torque is one of those "invisible" specs, and it has a bigger effect on club performance than you might expect.
Torque is defined as "a force that produces or tends to produce rotation or torsion." If you think of a golf shaft as an axis, the heel of the head is centered on that axis, but the toe – as well as most of the clubhead's weight – is off-center. When you swing the club, the head twists around the shaft. The toe gets "left behind" as you start your downswing, then it "catches up" and returns to its normal position at impact. The shaft resists that twisting motion, allowing only a certain amount. The twisting that is allowed, measured in degrees, is the shaft's torque.
A low-torque shaft may allow only 2 degrees (or less) of twist, while a high-torque shaft might go all the way to 6 degrees. That might not sound like a lot, but it certainly can affect your accuracy. Not only that, but if you hit the ball off-center – especially near the toe – it can increase the twist and cost you both distance and accuracy. A little torque goes a long way, so you obviously want the smallest amount of torque as is practical.
The material used to make your shaft matters. While torque always has been a factor in shaft performance, the inherent stability of steel shafts made torque relatively unimportant to everyday golfers. With the introduction of graphite shafts, however, manufacturers now can tailor shafts to behave anyway they want; they can duplicate the performance of any material from classic hickory to high-tech steel. But this comes at a price; the less torque you want, the more you have to pay for it.
The Right Amount
Fortunately, most players don't need shafts with extremely low torque. Not only does a little torque add feel to your shaft, it helps you create more clubhead speed. Although it's not the only factor, slower swingers usually benefit from higher torque, while hard-swinging pro golfers usually lean toward lower torque. Your club fitter also will take other aspects of your swing into account – how early your wrists uncock, how much effort you put into that uncocking motion and other shaft specs such as shaft flex, kick point and swingweight. For most average players, a medium-torque shaft works just fine.