Shaftuner

We match your driver to your favorite club

                                                How  Iron Heads Were Tested

Our tests prove that all models of iron heads, once they are assembled with the exact same shaft, perform equally in spite of  their metal alloy makeup, formed by casting or forged, shaped as cavity back of muscle back or their measured COR (trampoline effect).

We have been bombarded with ads from the major club manufacturers promising improvements from last years models in their latest iron head designs. They  move the weight distribution up one year and down the next. They hollow out, add plastic inserts and increase the complexity of the back of the face that never contacts the ball. The design of the face that the ball sees is constrained by the USGA rules on spacing, shape and depth of the grooves, even the radius of the groove edge where it merges with the face, the surface finish, and an 0.83 limit on the COR. With all these constraints, the club manufacturers hands are tied. So don’t look for a lot of improvement in spite of their claims. Be suspicious of any claim that uses the word “promotes” when referring to a “benefit”.  These words reflect luke warm enthusiasm  and defense against being proven wrong.

But let’s not get ahead of ourselves. Here are the tests that I administered to prove that iron heads have not improved much, at least in the last 20 years. To compare iron head designs, a mix of muscle backs and cavity backs were randomly selected to form a 6 iron head-test set. A few designs were 10 years old and some more recent. Some were cast and some forged. The Wishon 770 cfe was reported to have a COR of 0.815, near the USGA limit of 0.83 and the rest varied down to 0.77 COR. While the head models varied between test clubs, all the other factors were held constant: shaft length, shaft model, swing weight and grip. So any difference in playability  could be attributed solely to the head design.

 





























  










Compare distance achieved by 53 players hitting 6 iron head models Display of average shot distance for 3 players hitting 6 iron models Compares distance achieved with 6 different iron heads

The chart on the left  shows the result of one player tested with the 5 different 6 irons from the head-test set of clubs.

He was able to generate a difference in average carry distance between iron head models of  less than one yard !

Even more shocking is the observation that the spread of distance from the longest to shortest shots was  larger for the cavity backed, called game improvement, head models than for the traditional muscle backed models.












Two more players were added for a total of three players tested hitting the same six iron head models shown above. Data from Player A who has a 14 handicap and player C with a 2 handicap is plotted along with Player B with a 12 handicap whose test was shown above.

The chart on the left shows that after only 5 or 6 shots, no matter the skill level of the player, all the iron heads we tested achieved almost identical average distances   






Finally, data from more than 50 players was added to the original three. The average difference  in distance hit between  iron head models, after 7 shots with each, ranged from 0 to 2 yards. No one could achieve more than a 2 yard difference between any of the iron head models we tested.

The average yardage difference between iron head models achieved by over 50 players tested was less than  1 yard!

Industry ads claiming iron head design improvements from year to year are just marketing hype. Keep your old irons and fix your driver.

        All Iron Heads are the Same

Example of pesent driver head waiting to be re-shafted

Driver Heads, unlike iron heads, have been improved quite a bit since metal heads were introduced several decades ago. The metalurgical progression from stainless steel to titanium allowed a doubling of head size and an increase in MOI and COR values as well as lessening the penalty of missing the sweet spot. But if your driver head is less than 5 years old, it is probably right up against the USGA design limits. The USGA is not likely to change the driver head design rules, so don’t expect very much improvement in the near future.

Why not re-shaft your present driver by matching it to your favorite 3W, hybrid or iron and save a lot of money. Let your playing partners spend their’s.