Stiff vs Extra Stiff Iron Shafts – How To Chose Iron Shafts For Fast Swingers

At what speed do you swing your driver? Would you classify yourself as a fast or slow swinging golfer? Our swing speed provides a point of reference for us to determine the ideal shaft flex for our clubs.

In this post, we are looking at stiff vs extra stiff iron shafts. If you are a faster swinging golfer, this article will help you determine if a stiff or extra stiff option is better suited to you.

Iron Shaft Flex And How It Affects Your Game?

The flex of golf iron shafts is classified as extra stiff, stiff, regular, senior, and ladies. The varying levels of flex help fast, moderate, and slow swinging golfers achieve their desired apex, spin, and consistent shot dispersion.

The team at True Spec Golf explains that the incorrect shaft flex can lead to ballooned or low shots, excessive or insufficient spin, and erratic shot dispersion.


How Important Is The Flex Of Your Golf Irons?

True Spec Golf says that the average golfer neglects the importance of shaft flex when purchasing new clubs. The reality is that we are often too focused on the marketing and features of the actual club that we forget about the finer details.

Using the correct flex for your swing helps you to achieve a consistent apex and shot dispersion, as well as desirable spin levels.

Employing the incorrect shaft flex can lead to extremely low or high ball flight, a loss of distance, and wayward shots.


In What Ways Does It Impact Your Game?

If you struggle to get your ball airborne consistently, you may find that your shaft is too stiff and heavy for your swing speed.

As a result, you generate limited spin, the ball flies low to the ground, and you lose significant distance. You may also experience low shots with a slice.

Contrarily, those of you who balloon your iron shots and generate excessive spin may be playing with a shaft that is too flexible and light for your swing speed.


How To Know Whether You Will Need Stiff Or X-Stiff Irons?

The best approach to determine the correct shaft stiffness for your swing is to get fitted.

A professional will assist you in making better-informed decisions when it comes to purchasing a set of irons.

Alternatively, you can follow this chart set out by and True Spec Golf. It provides insight into what shaft flex suits your swing speed.

Swing Speed Vs Shaft Flex Table Table

The below table features the average clubhead speeds with a 6-iron for different categories of swingers. The below information can be found in this article by Zephyr Melton.


Swing Speed

Clubhead Speed

Shaft Flex

Super Fast

> 92mph

Extra Stiff


84 – 91 mph



75 – 83 mph



65 – 75 mph


Super Slow

< 65 mph



What Flex Irons Do The Pros Use?

Golfweek’s Jim Thomas sums it up simply in this article, where he states that the majority of PGA Tour Pros use stiff or extra stiff shafts.

However, just like us average golfers, the iron shaft flex that Pros use will ultimately come down to personal preference.

Pros And Cons Of Stiff Iron Shafts


  • Promotes a lower launch
  • Enhanced control
  • Suited to fast swinging golfers
  • The best shaft type for accurate short game dispersion


  • Golfers with slow swings will struggle to consistently launch the ball skywards.
  • Low level of spin
  • Players with a super-fast swing may find a stiff flex shaft too flexible, causing them to balloon shots and lose distance.


What Type Of Shots Does It Lead To?

The correct shaft will help you achieve your desired shot shape.

Obviously, if you are using super game improvement irons, your aim is to achieve a straighter flight. While superior golfers, who use blades, will be looking for more shape.

However, if you are a moderate to slow swinger, a stiff shaft may offer too little flex, resulting in a slice or a fade. Conversely, if you swing the club super fast, a stiff shaft may provide excessive flex causing you to sky your shots and lose distance.


Pros And Cons Of X-Stiff Iron Shafts


  • Offers a tighter shot dispersion to super fast swinging players
  • Made for players with driver swing speeds above 92 mph
  • Enhanced control over your launch height


  • Slower swinging golfers will struggle to get the ball airborne consistently with these shafts.
  • The additional stiffness can lead to slow swinging players slicing or fading their shots.


What Type Of Shots Does It Promote?

If you are a faster swinging golfer, you will enjoy tighter shot dispersion and a more controlled trajectory with an extra stiff shaft.

However, slower swinging players may find that an extra stiff shaft reduces the apex of their launch and promotes a slice or a fade.


How To Know If You Need To Change To X-Stiff Irons?

If your shots are launching higher than desired, causing you to lose distance, then it is worth considering extra stiff irons.

The less flexible construction keeps your clubhead in the desired position at impact, enabling you to achieve your preferred shape.

As a rule of thumb, if you swing a 6-iron above 92 mph, then an extra stiff shaft would be the best fit.

However, I recommend getting fitted for your iron shafts to ensure that you use data and expert advice to make a better-informed decision.


Signs Your Irons Shafts Are Too Flexible?

True Spec Golf has found that your shaft is too flexible when you balloon your shots.

Those of you who are ballooning your iron shots or generating excessive levels of spin may be playing with a shaft that is too flexible for your swing.

As a result, you will experience an erratic shot dispersion and loss of carry, and total distance.


How To Know If You Need To Change To Stiff Irons?

As I mentioned earlier, faster swinging golfers tend to balloon shot and generate excess spin when they are playing with a shaft that is too flexible.

If you are using a regular flex shaft, but are experiencing the above problems, then it is time to switch to stiff flex irons.

Conversely, if you use x-stiff shafts and are unable to achieve a consistent moderate to high launch.

And, generate low levels of spin, then it is worth considering a more flexible option such as stiff shafts.

The most effective way to determine the correct shaft flex for your swing is to get fitted by an expert.


Signs Your Irons Shafts Are Too Stiff?

Those of you that consistently slice or fade your shots or achieve a low trajectory may benefit from a more flexible shaft.

A shaft that is too stiff will prevent you from positioning your clubhead in the correct position at impact, to achieve your desired shape and trajectory.

As a rule of thumb, if you are swinging a 6-iron below 84mph. A stiff or extra stiff shaft will likely be too much for your swing.


What Other Flex Options Are There?

Besides the x-stiff and stiff shafts best suited to faster swinging players, there are options for slower swingers. If your swing speed with a 6-iron average between 75 – 83 mph you consider a regular flex shaft.

On the other hand, if your average 6-iron swing speed is 65 – 75 mph, then a senior’s flex is your best bet. Finally, those of you who swing a 6-iron below 65 mph should consider the ladies’ flex option.


Are X Stiff Irons Shafts Heavier?

Golf Monthly’s Neil Tappin explains that stiff shafts are firm and more difficult to bend than a regular shaft and are heavier as a result.

Therefore, since stiff shafts are weightier, the additional firmness of an x-stiff design makes it the heaviest shaft.


How Is A Heavier Shaft Going To Affect Your Game?

TPT Golf explains that heavier shafts can help you generate increased swing speed.

They are confident that a heavier shaft forces you to work all your muscles and get behind your swing, resulting in more speed.

However, if a shaft is too heavy for swing, you will struggle to generate spin and ball speed. This leads to a low ball flight, and loss of carry, and total distance.


Conclusion On Stiff vs Extra Stiff Iron Shafts

Stiff Iron Shafts

Our review on stiff iron shafts demonstrates that they are designed for fast swinging golfers with an average 6-iron swing speed of between 84 mph to 91 mph.

If this describes you, it is worth considering the use of stiff iron shafts to complement your swing.

However, super fast swingers with a 6-iron speed above 92 mph may enjoy the ease of launch offered by a stiff shaft.

Conversely, if you are a slow swinging player, you may enjoy the lower launch provided by a stiff shaft.

Extra Stiff Iron Shafts

Throughout our post on stiff vs extra stiff iron shafts, we have identified that the stiffest shaft on the market is only suited to super fast swinging golfer’s. You fit into this category if you swing a 6-iron above 92 mph.

Slower swinging golfers will likely find that extra stiff iron shafts deliver an inconsistent degree of launch and a loss of distance.

Overall Conclusion

The moral of the story is that if you consider yourself to have a fast swing, you should consider stiff iron shafts.

But if you are a super fast swinging golfer, the extra stiff shafts are the way to go.