What Is Shaft Torque?

Torque is the simply the amount a shaft (shown in blue) twists when subjected to a known amount of force (usually one foot-pound of force is applied) and the torque value is always expressed in degrees. It is a term commonly associated with composite or graphite shafts, but steel shafts have a certain degree of torque too. However the amount cannot be independently changed from the frequency (or stiffness) of the shaft like a composite design, thus torque of steel shafts is generally not listed by the manufacturer. A lower torque value (i.e. 3.5° versus 4.5°) resists the shaft from twisting on the downswing with all else equal.

Is there a standard?
The answer to that is no, just like most parameters in the golf industry. I like to say “the only standard in the golf industry is there are no standards.” Each manufacturer has an internal method for measuring torque that will vary from one to the next. However, each shaft by the manufacturer will be measured using the exact same clamping dimensions and force for all their shafts. To explain this, let’s look at the following diagram.

The top shaft shows how Hireko measures torque for our Dynamic Shaft Fitting Index. We clamp 1” of the tip where the tip weight or force is applied. Of course for this to occur, the butt end is clamped (in our case 2”) to secure the shaft. The difference between the clamps is called the beam length. At Hireko, we measure a longer beam length than any manufacturer which is important to know when looking at out listed values versus those by the actual manufacturer.

For the sake of example, this 46” raw shaft (with a 43” beam length) happens to measure a torque of 6.0º using 1 foot-pound of force. By most standards, this torque rating may seem high.

Now let’s take the same exact shaft and change the clamping dimensions. Some manufacturers may elect to clamp 3” up from the tip and use a 32” beam length on their woods. This means the butt end of the shaft is clamped 11”. While this may sound like a lot of shaft is not being included for the torque measurement, there may be a valid reason. Some manufacturers have been measuring torque on their shafts since the days when wooden woods were common. In those days the shaft would exit the head 3” from the tip. Plus the shaft would be cut to length and not used at its full length. The clamping dimension further down the butt end would be closely associated with the position of the lower hand or portion of the grip.

By changing the beam length, the torque value of this shaft goes from 6.0º down to 4.3º, which is no longer considered high, but more average for a wood shaft. None of the manufacturers that I am aware of show how their torque is measured. So comparing torque values from manufacturer to manufacturer is not an exact science like it is by looking at the values from shaft-to-shaft with one particular company’s product line. This is one of the reasons why Hireko continues to test all parameters using the same testing methods and publish those results in our annual Shaft Fitting Addendum.

Is lower torque better?
The one thing about torque is that it is perhaps the most misunderstood shaft parameter and to the bewilderment of many, may not make complete sense. There is a myth out there that the lower the torque the better and will result into a straighter shot. While that may had started in the early days of graphite production, this is not entirely true today.

One of the reasons shafts with higher torque values are considered less accurate can be attributed to the cost. Often times the higher torque wood shafts (above 6°) will be less than $9 retail and may not be 100% graphite, but have a certain percentage of fiberglass mixed in. One clue is to look at the shaft weight. A heavier weight will be a sure sign that is contains a high percentage of fiberglass. Some shafts that are found in boxed sets or very inexpensive composite shafts contain fiberglass.

Low cost graphite shaft are constructed with low modulus (lower strength) materials. Often times these shafts will exhibit both high torque and a softer tip section. In the hands of a stronger player, this combination would be less accurate than a lower torque model.

But not all higher torque shaft use low modulus material. Contrary, some of the world’s most expensive shafts have higher torque values and here are a couple reasons why. With the advent of 4-axis winding, manufacturers might elect to wrap high modulus graphite plies at 0º angles on the mandrel to increase the hoop strength and control shaft ovalization allowing for better shot consistency. These fibers have no contribution to the torque of the shaft.

Secondly, shaft weight plays an important factor. If you do not believe me, look at any shaft line that is produced in different weight options. It should come as no surprise that the lighter the shaft; the higher the torque value. When you think about it, this makes complete sense. If less material is used (due to the lighter weight), there is less material available to control torque or resist twisting.

This year will there will be a focus or at least a trend toward lighter and lighter weight drivers. These drivers will be using shafts in the 50 gram and even lighter range. All of these super-lightweight shafts will require better quality materials to achieve the target weight and limit breakage. As a result of the thinner walls these shafts may have torque value by the manufacturer close to 6º (or 8º using Hireko’s longer beam length method), yet will produce highly playable clubs.

If you have control problems with these lighter weight / higher torque designs – don’t blame the torque. Blame the longer assembly length or the potential that the club is just too light for you to handle. Additional torque could actually be your friend, especially if you tend to fade, push or slice the ball as this could help to close the club face and not resist it.

17 comments

  1. Eric Swanson says:

    great article! thanks for posting Jeff!

  2. dave ellison says:

    excellent presentation on torque. very clear and understandable. congratulations.

  3. wally says:

    Thanks for a great article…explains some of the smoke and mirrors

  4. Richard Berger says:

    Jeff;
    Are we correct to understand that higher torques will tend to close the face at impact and that a shaft with too much resistance (lower torque) will tend to leave the face open at impact and lead to the ball slicing or being pushed? Is there a relationship between swing speed and correct torque?

    This was a great piece. I wish you could have gone just a little further…

    Thanks,

    R…

  5. Jeff Summitt says:

    Richard:

    I have to be careful how I answer your question because often time you change one parameter (such as torque), it might influence another like tip stiffness or frequency (stiffness). If you look at your question at face value, then the higher torque can help close the club face with all else being equal. However, heads with different CG locations can also play a role as the club works as a system.

    A person with reduce swing speed will often produce less torques or forces on the club than someone with higher swing speeds. So selecting torque might go hand in hand with flex. For example if you are using a more flexible shaft (like A or L), then chances are you may not require as low of a torque value shaft. But then again there are many other factors to consider as torque and flex can be designed separately of one another.

  6. Richard Berger says:

    Thanks, I’m starting to get it, I think…I can be more specific: I’m planning on building a new driver with the Leggera head. I want a lightweight shaft…my swing speed is about 85 mph. If I miss, it’s usually to the right except for a pull hook once in a while (not often). Any shaft recommendations? I’m a senior (63).

    R…

  7. Don says:

    Your statement that graphite plies at 0 degrees does nothing to control torque, is not what I have read in the past. I have read information from a few high end shaft companies that state that plies at 0 degrees do reduce torque, plies at 90 degrees control stiffness, and plies at 45 degrees control both, but to a lesser extent. Plies at 30 degrees do the same thing as plies at 45 degrees, but in a different amount.

  8. Jeff Summitt says:

    Richard:

    It will depend upon what you are using to a certain degree. You could be missing right because of the face angle, shaft weight, flex, length, etc. Shaft flex will have little if any to do with age, sex or handicap – only your speed and your tempo.

  9. Jeff Summitt says:

    Don:

    The 0 degree plies (some manufacturers might call this 90º and longitudinal 0) are used primarily in the butt section. The majority of the shaft torque occurs in the smaller diameter tip section. A way to check is to clamp different amounts from both ends and measure the differences. You might be able to clamp 10″ of the butt and see he same change as clamping 1″ more from the tip.

  10. David Lord says:

    I have some disagreements with your explanations. 1. Almost all the torque occurs at the tip where the shaft diameter is least. The resistance to torque is a 4th power function of the shaft diameter.To demonstrate this, paint a narrow line the length of the shaft and apply a twisting load to the tip per the diagram of the article. You will see where the twist occurs. It will be pronounced at the tip and diminish very quickly as you move toward the butt end. At one foot or so toward the butt the twist will be negligible.I would agree that the longitudinal plies resist flex. The 0deg. plies resist torque only. The 45deg. plies resist fractionally both torque and flex depending on their angles. A 45deg. angle ply splits the resistance to torque and flex equally. The advantage of the filament wound shafts is that the angle of the filament can be changed as it proceeds from the butt to the tip so that the designer has some limited flexibility in addressing torque and stiffness.

  11. Mike Yee says:

    Jeff, what is your opinion on shaft “spining”? I’ve had my Driver’s SST Pured,… and woods “spined” at 9 O’clock position. Very noticable difference in distance and consistency using both technologies.

    I’ve heard that the 3 O’clock position offers more accuracy/consistanc but less distance than the 9 O’clock position. And that either the 12 or 6 O’clock positions help prevent “toe drop” or bend during the downswing.

    Any thoughts? I searched the site for previous posts on spining, but couldn’t find anything.

    Thanks

  12. Jeff Summitt says:

    Mike:

    You may have to attribute the distance and consistency to finding the right head and shaft combination. It may have nothing to do to the position the shaft was placed. The only way to know is if you have the shaft carefully extracted and reassembled in a haphazard position other than what you had it in (like 45 degrees one way or another)and then you can see if Puring did anything in performance.

  13. […] are identical to one another except for the torque, with the Beta a degree higher according to how we measure torque (which is always a higher reading than the manufactures publish as we measure a greater beam […]

  14. Don Thompson says:

    Jeff,
    I have had much conversation about understanding torque and much has been with Charlie Blume. You don’t mention anything about torque also being relevent to trajectory. It’s hard to understand or explain as Charlie puts it but torque also can affect flight trajectory (height). Do you agree or disagree with Charlie? Don

  15. Jeff Summitt says:

    Don:

    It is complex to explain because you usually can’t change torque independently without changing other parameters such as materials and tip stiffness to name a few. The closest shaft to maintaining all other parameters is the UST VTS line. But yes, I have seen subtle changes to ball flight which could be explained by differing spin rate, dynamic loft (tip stiffness) or face attitude (open or closed) upon impact. Not only that, but you change the feel of the shaft. When you do that in the hands of a human, that can also change how they swing the club.

  16. Jack says:

    I realize if i tip trim a say a shaft of 5 iron from 38.5″, then tip it .5″ more I’ll gradually have s firmer shaft.
    What will occur to Apollo Acculite 95 Steel flex if I butt trim .5″?
    What will occur to Apollo Acculite 95 Steel flex if I butt trim 1″?
    Will the shaft become stiffer or softer, and how much?
    I realize the swing weight will change.
    I can adjust that if necessary.
    Is there anything I should be aware of if I try this (butt trimming)?
    Thanks for your input.

  17. Jeff Summitt says:

    Jack:

    I am going to assume you don’t change the tip trimming. The shaft (and club) will register a higher cpm indicating a stiffer shaft if you don’t alter head weight. This is due to a lower swingweight. At 1/2″ shorter it will be 3 swingweights higher and subsequently 3 cpm. At 1″, it would be 6 swingweight points and 6 cpm higher. However, if you were to use a 7g heavier head for the 1/2″ shorter, then that will decrease the cpm back down 3 points. Because you have a shorter club at the same frequency, it makes it a more flexible club.

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