Mizuno Pro Signature Series S-3 Irons

Posted by GolfBox on 7th Jan 2025

After the Mizuno Pro 241, 243 and 245 irons launched 15 months ago to widespread acclaim and adulation, an intriguing new iron inserts itself into Mizuno’s flagship forged iron line-up in 2025.

The new Mizuno Pro S-3 iron is the start of something new for the Japanese manufacturer, yet is also very familiar. A compact, tour-inspired cavity back, the Pro S-3 launches the new Mizuno Pro Signature Series — a range of classic forged irons that takes Mizuno back to its roots.

THE NEW SIGNATURE SERIES

As the manufacturer of some of the most iconic forged irons in the game, the new Mizuno Pro Signature Series iron range sees Mizuno return to what it has always does best.

Mizuno has unashamedly designed the new Pro Signature Series irons for the best players in the game. The target demographic is elite golfers who want to hit draws and fades and work the ball through the air, aided by Mizuno's inimitable forged feel.

The new Pro S-3 is the first of four irons in the new range. In time, it will be joined by an S-1 and S-2 muscleback blade and another cavity back iron, the S-4.

IT SEEMS FAMILIAR?

Featuring a split cavity-back construction, a sleek and compact profile, thin topline and narrow sole, the Pro S-3 is based on Mizuno's JPX Tour iron.

Back in its heyday in the 2010s, the JPX Tour iron won several major championships. But as the popularity of the player's-distance Hot Metal models in the JPX line grew, the Tour model seemed to get lost in the line-up.

Mizuno didn’t release a Tour model in the latest JPX925 line. Instead, they pulled up stumps and rebranded the Tour as the new Pro S-3.

For now, the Pro S-3 will slot somewhere between the Mizuno Pro 241 and 243 (probably closer to the 243). The Pro S-3 is fitted with a split cavity that is much smaller and shallower than the Pro 243, but it does feature a slightly longer blade length.

FORGED FOR FEEL

Like all of Mizuno’s forged irons, the Pro S-3 iron is crafted using Mizuno’s renowned Grain Flow HD technique. The process was invented by Mizuno to elevate feel by straightening and preserving the natural grain of the metal in the forging process.

In the case of the Pro S-3 iron, that metal is supple 1025E mild carbon steel. It provides a soft and responsive feel and touch that is improved exponentially by an additional layer of copper added after the forging process.

The copper layer elevates the soft feel to another dimension while also reducing unwanted vibrations, to provide refined feedback.

TRIPLE CUT SOLE

The Pro S-3 features Mizuno’s new triple cut sole, which is designed for consistent and efficient turf interaction. It’s identical to the sole on Mizuno’s new JPX925 Forged iron.

The leading edge is slightly bevelled to prevent the Pro S-3 digging into the turf too much, while its trailing edge is sharper — which helps the club exit the turf quickly and efficiently.

Meanwhile, slight relief has been taken out of the heel and toe in the centre of the sole to increase versatility, improving performance out of all kinds of lies encountered on the golf course.