Mizuno JPX921 Forged Iron Review

Published: 10 August 2020 Last updated: 06 October 2023

At a glance
TG Rating 5 out of 5
Owner Rating Not yet rated
RRP £150.00

What we say...

The Mizuno JPX921 Forged is the brand’s first full body forged chromoly steel iron. We examine what type of golfer should have it in their bag.

When Nike pulled the plug on its golf club business in August 2016, it sent shockwaves through the game and meant big-name players like Tiger Woods, Rory McIlroy, Brooks Koepka, Tony Finau and Paul Casey were all left without equipment contracts, which was unprecedented.

But nobody could have predicted how Nike’s exit would help the Japanese brand, and ultimately lead to this new JPX921 family of golf irons.

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Four years ago, Mizuno were still seen as a traditional forged iron company, the type that made brilliant musclebacks with shiny finishes (that are bought by less than 1% of golfers). With sales of forged irons falling, the JPX family – with their funky colours, cartoon-style ads and satin finishes – we’re designed to draw in a younger audience, but they failed to generate the sales Mizuno expected.

Mizuno JPX921 Forged Iron

Step forward Mr Koepka (the person Mizuno had created JPX for, before Nike swooped in and signed him). As a free agent he decided the JPX900 Tour irons were the perfect fit for his game. He liked them so much, he was happy to play them for nothing.

Brooks then went on to win the 2017 US Open, defend that title in 2018 and bag the US PGA, all with a set of Mizuno irons. The feat single-handedly rebooted Mizuno’s JPX iron family and attracted that new, younger golfer.

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Once Mizuno revealed its replacement, the JPX919 Tour, the big-hitting American put them straight into play and defended his US PGA title in 2019. The four-time Major champion single-handedly has been the making of JPX, and now it’s time for the new models.

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Mizuno JPX921 Forged Iron

RRP: £150 per iron

Availability: 4-GW

Stock shaft: Nippon Modus 120/105

Stock grip: Golf Pride MCC +4

7-iron loft: 31°

If there’s a headline grabber among the JPX921 family, this is it. Mizuno refer to it as their smoking gun and are very proud they’ve pulled off the first full-body forged chromoly steel iron as the energetic material isn’t easy to work. The new 4120 material means less ball speed leakage over the 919 Forged.

The Forged has been squeezed slightly more towards a players iron than previous models, thanks mainly to smaller, slimmer scoring irons.

Mizuno say it is perfect for golfers who want a bit of everything (forged feel and sound, fast ball speeds, great looks and a degree of forgiveness), but don’t want to compromise on anything to get it.

Mizuno JPX921 Forged Iron

What you need to know about the Mizuno JPX921 Forged irons

Faster, Forged and First

Mizuno have used chromoly steel in the JPX iron family for a few years, but it’s always been cast, not forged.

Mizuno knew if they could work out a way to forge chromoly steel they’d be onto an absolute winner, as it’s such an energetic material.

This iron is forged from 4120 chromoly steel an it’s the first forged full-body chromoly steel iron ever produced.

Sleeker and more compact

The JPX921 Forged has been squeezed more towards the player iron market (than the previous JPX919 Forged), there’s a shorter blade length and reduced offset to cater to the eye of better players.

A bevelled trailing edge improves turf interaction, which helps players who hit down on their irons and engage the turf.

Mizuno JPX921 Forged Iron

Extra performance from a smaller head

You won’t often hear brands say they’ve reduced an irons head size and improved forgiveness, but that’s exactly what Mizuno claim with the JPX921 Forged.

A CNC Milled slot behind the face is 6.4% wider, the face is 0.5mm thinner which increases stability in what is a smaller club head than the previous JPX919 Forged.

A little less loft

Mizuno have never played the loft-jacking game, as they insist a 7-iron needs to take off and land like one.

But the JPX921 Forged (4-8 iron) are one degree stronger in loft than previous models. Our testing has shown they launch and fly higher and land at a steeper angle than their predecessor.

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What Mizuno say about the JPX921 Forged iron

“By applying the potential of Chromoly steel the JPX921 Forged iron can hold its own in any simulator test – without having to crank #7 iron lofts,” saidDavid Llewellyn Director of R&D for Mizuno.

“For an iron to perform the look, feel, launch, spin and landing angles have to be right through the set, which ultimately is what sets Mizuno irons apart.”

Mizuno JPX921 Forged Iron

Data comparison: Mizuno JPX921 Forged, Tour, Hot Metal and Hot Metal Pro irons

Mizuno JPX921 Forged Iron

Verdict: Mizuno JPX921 Forged iron

When your whole business is built on the success of forged irons and your craftsmen have been forging clubs for 115 years, you push at boundaries others dare not touch – and that’s Mizuno’s thinking with the JPX921 Forged.

Taking chromoly steel (well known for being springy and lively) and stamping it into a mass-market forged iron was a challenge Mizuno happily accepted. And their experts now think forged chromoly steel has a very bright future. The JPX921 Forged offers a brilliant blend of narrow top edges that lots of reasonable players like, along with a forgiving undercut cavity.

Mizuno say they suit 10-14 handicappers brilliantly, and we’d agree. Lots of golfers find themselves choosing between these and Mizuno’s hollow body MP-20 HMB. Our latest test data has the 1° stronger (7-iron) Forged adding 1mph of ball speed and two yards of carry over the HMB. Just remember the face in both irons is chromoly steel, and if you’re stuck between the Forged and the JPX921 Tour, we’ve seen 8 – 11 yards of 7-iron carry difference in favour of the Forged.