Mizuno JPX923 Hot Metal Iron Review

Irons expert Joel Tadman tests the latest game improvement iron from Mizuno to find out what golfers can expect

Mizuno JPX923 Hot Metal Iron Review
(Image credit: Future)
Golf Monthly Verdict

A very playable, forgiving distance iron that offers a softer feel and greater stopping power than most among its competitive set. Not a huge leap forward from the JPX921 version, but the changes in the sole make it noticeably more user friendly.

Reasons to buy
  • +

    Appealing looks all round

  • +

    A fast but controlled feel

  • +

    Excellent stopping power

  • +

    More forgiving through the turf

Reasons to avoid
  • -

    Limited gains over prior model

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Mizuno JPX923 Hot Metal Iron Review

Mizuno has utilised the Swing DNA data collected from its impressive Shaft Optimiser 3D technology to shape the new range of JPX923 irons. Specifically, it noticed a trend towards more shaft lean being presented to the ball across the handicap spectrum, and as a result has added some bounce and camber to the sole to improve the turf interaction on offer.

VIDEO: Watch Joel Tadman test and compare all three Mizuno JPX923 Hot Metal irons

The Hot Metal is billed as the longest iron in the JPX923 range, in part down to having the strongest lofts which have actually got up to 1.5° stronger compared to the prior JPX921 Hot Metal iron depending on what area of the set you’re looking at. In the 7-iron we tested, though, the loft has only got half a degree stronger coming in at 28.5°.

Visually, the new version looks somewhat similar - the amount of black paint fill on the back has reduced on the JPX923 Hot Metal and the Mizuno Running bird logo added to the toe. At address, you could make a case for there being slightly less offset and the head being a fraction smaller overall.

mizuno jpx923 hot metal iron address

(Image credit: Future)

Many of the changes from the previous generation you won’t be able to see. Specifically the switch to 4335 Nickel Chromoly, a stronger material that has allowed for an eight percent thinner face. Our testing on the Full Swing Kit launch monitor with Titleist Pro V1x golf balls would suggest the performance hasn’t moved on a huge amount versus the JPX921 Hot Metal, although we did notice a higher launch and ball flight overall despite the stronger lofts. It’s refreshing to see distance irons spinning close to the 6000rpm mark - it’s no good hitting the ball far with your irons but not be able to stop the ball on the green. When combined with the higher trajectory and a healthy descent angle, you should be able to attack pins here without fearing the ball bounding over the back of the green.

mizuno jpx923 v 921 hot metal irons data

(Image credit: Future)

The other main thing I love about this iron is the feel. It doesn’t have that explosive, metalwood like feel you often get from game improvement irons. In fact, it is as close to a forged-like feel as you’re likely to experience in this category, producing a dense sensation at impact and a relatively quiet sound to match.

mizuno jpx923 hot metal iron testing

(Image credit: Future)

The turf interaction has changed too. There’s certainly more resistance through the turf, which will help if you catch the ground slightly before the ball and create smaller, shallower divots. If you’re a picker of the ball, you may struggle to get the club under the ball, but for the majority this will be a welcome change.

Considering this is the least expensive iron in the new JPX923 iron range (£135 per club) you're getting a lot of performance for the money as well as that signature feel and playability you expect from the best Mizuno irons. Slower swinging golfers may want to consider the new Hot Metal High Launch option, but the majority of mid-to-high handicappers will likely be able to get more out of this iron versus what is currently in their bag.

Joel Tadman
Technical Editor

Joel has worked in the golf industry for over 12 years covering both instruction and more recently equipment. He now oversees all product content here at Golf Monthly, managing a team of talented and passionate writers and presenters in delivering the most thorough and accurate reviews, buying advice, comparisons and deals to help the reader find exactly what they are looking for. So whether it's the latest driver, irons, putter or laser rangefinder, Joel has his finger on the pulse keeping up to date with the latest releases in golf. He is also responsible for all content on irons and golf tech, including distance measuring devices and launch monitors.


One of his career highlights came when covering the 2012 Masters he got to play the sacred Augusta National course on the Monday after the tournament concluded, shooting a respectable 87 with just one par and four birdies. To date, his best ever round of golf is a 5-under 67 back in 2011. He currently plays his golf at Burghley Park Golf Club in Stamford, Lincs, with a handicap index of 3.3.


Joel's current What's In The Bag? 

Driver: Titleist TSR3, 9° 

Fairway wood: Titleist TSR3, 15° 

Hybrid: Titleist TSi2, 18° 

Irons: TaylorMade P770, 4-7 iron, TaylorMade P7MC 8-PW 

Wedges: Titleist Vokey SM8, 50°, 54° and a Titleist Vokey SM9 60° lob wedge 

Putter: Evnroll ER2V 

Ball: 2021 Titleist Pro V1x