Growing Family

Eighteen months after the S-3 appeared and a year after the S-1 arrived, Mizuno has launched the third club in the same S series – the S-4

By Tony Dear

Readers will know how the number of golfer categories is constantly evolving…as far as club manufacturers are concerned, at least. There used to be good and poor, which became good, not-so-good, bang average, not-so-poor, and poor, with more rungs on the ladder appearing every so often. As golfers have become more demanding, choosy, and specific about what club features and characteristics they need/want, so manufacturers have increased the number of clubs in their inventories to meet the golfer’s ever-expanding awareness of their own game (and yes, clubs we didn’t know we needed until being told we need them by manufacturers probably exist too, right?)

There are truly elite ball-strikers, whose names you probably know, who want the most compact and simplest of blades for feedback, feel, and workability. But there are also plenty of very good golfers who might be getting on in years and have lost a little clubhead speed, and who have always played blades, and who still want a blade-adjacent club but with a little added forgiveness or ballspeed-boosting features.

All of which brings us to Mizuno which currently makes nine different irons for golfers whose talents, demands, and needs overlap a good deal. Suffice to say, the lines between iron categories are getting ever more blurred.

Within Mizuno’s nine-strong line-up are three classes of iron – Pro S (timeless, forged, classic), Pro M (still played by the Mizuno loyalist but with a little more tech), and JPX (multi-material, perhaps a little more experimental, embracing new tech). All are geared towards, if not the better golfer, then certainly the more committed, regular, seasoned, and serious golfer. There are no half-measure clubs here for half-hearted golfers.

The new S-4 is the third iron in the Signature series. The shallow cavity-back S-3 appeared in January 2025, while the S-1 blade followed in July. The S-4 is the most forgiving of the three, with a lower CG – thanks to a curved muscle – that produces a higher launch, leading to a steeper angle of descent and, hopefully, a shot that stops before bounding over the back of the green.

But it is still compact, forged from a single billet of 1025E Mild Carbon Steel with a copper underlay for improved feel, and clearly meant for the serious golfer. The wider Triple-Cut sole has beveled leading and trailing edges to cut through the turf efficiently. And it’s progressive – the sole getting wider and the offset increasing as the club gets longer. The top-line also gets a little thicker on the longer irons to inspire confidence.

So yes, there are some subtle design features in the S-4 that will make the better-than-average but less-than-elite golfer happy.

$215/club
Lofts – 4-24̊ , 7-34̊ , PW-46̊
Shaft – True Temper DG Mid 115 (46 custom shafts available
3-PW in right-hand, 4-PW in left-hand
Available at mizunogolf.com and at retail starting Sept. 17^th.