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Mizuno's JPX range has been around for quite some time and provides a more playable offering of irons than the forged blades that first helped the brand to make their name.

Mizuno JPX923 Hot Metal Irons

Alongside the sleeker JPX923 Tour and Forged, Mizuno are also offering three distinct versions of the Hot Metal irons which have typically produced a little more speed with a higher launch.

The Tech

The Hot Metal Irons feature Nickel Chromoly for the first time, a material which provides higher levels of ball speed, allowing Mizuno's engineers to focus on improving feel and stopping power.

Mizuno JPX923 Hot Metal Irons

Nickel Chromoly is 35% stronger than the materials usually used in Hot Metal irons, which allows for an 8% thinner clubface to help produce higher ball speeds.

There's a cup face construction that positions the centre of gravity deep in the head which is needed for a high launch and steeper landing angles to produce better stopping power.

Mizuno JPX923 Hot Metal Irons

The thinnest section of the sole has been made 18% wider compared to the JPX921 irons, providing a larger sweet spot on the face for more consistent ball speeds.

This year Mizuno are offering three different Hot Metal models, after data from their Swing DNA system indicated the need for different launch options.

The Hot Metal Pro is a 'player's speed cavity' which is compact with hardly any offset, aimed towards confident ball strikers who are looking for a bit of extra ball speed and best suited to low to mid handicap golfers.

The standard Hot Metal is a slightly more forgiving iron which is aimed at mid to high handicap golfers. It features a full, high stability cavity which is built for a straight flight and distance.

The Hot Metal HL is a high launch iron which encourages a higher ball flight for golfers with slower swing speeds or who deloft the club at impact. It's suitable for mid to high handicap golfers.

Mizuno JPX923 Hot Metal Irons Review

Looks and Feel

For me, Mizuno's Hot Metal irons have always been one of the better looking game improvement irons, both in the bag and at address, which probably helps it to retain appeal with a wider number of golfers.

Mizuno JPX923 Hot Metal Irons

The latest generation of the JPX irons look very similar to the JPX921, with very similar shaping and sole design. The running bird logo has been moved higher up in to the toe in the new Hot Metal irons, in just the same way that it was on the JPX919 Hot Metal iron.

The brushed satin finish, which has been a trademark of Mizuno's JPX irons for me over the last few years, looks great both in the bag and down by the ball.

The Hot Metal HL has a very large footprint down by the ball with a thick, rounded topline, whilst the Hot Metal Pro is the sleekest of the three models and looks great down by the ball. It provides just enough size to still help you feel confident over the ball without being too big, so that it still seems workable.

Mizuno JPX923 Hot Metal Irons

As you move into the long irons these do start to get quite chunky, particularly in the standard Hot Metal and the Hot Metal HL, which place them more towards the higher handicappers in the mid teens and above.

Mizuno JPX923 Hot Metal Irons

Sole widths continue on the same theme - the standard Hot Metal and the Hot Metal HL are quite generous in width whereas the Pro reminded me more of the TaylorMade P790 or my own Callaway Rogue ST Pro irons.

Mizuno have been quite clever in that they have designed the sole with a specific pattern which makes it look thinner than it really is, by allowing some of the shiny chrome from the back of the head to wrap around on to the sole.

Mizuno JPX923 Hot Metal Irons

The irons felt pretty hot coming off the face, and it felt easy to generate both ball speed and distance. I don't often like to hit shots full out as I feel like I lose control, and all three of these irons felt like they were going to launch well and travel a good distance without having to try and really hit them hard.

I wasn't a massive fan of the sound, particularly in the Hot Metal and Hot Metal HL, as it was just a little too loud and clicky for me having been used to something a little more muted with my own irons.


The three irons all produced good numbers, and I was impressed by the consistency between the worst and best shots for all three, which is a sign of the high forgiveness levels even when you don't catch it right out of the middle.

I found the spin rates were pretty low, with all three coming in at less than 5000rpm with the 7 iron. However the lofts are pretty strong (HM and HM Pro 28.5 HM HL 31) and the launch angle and peak height was higher than usual, meaning that stopping distances were still good.

Mizuno JPX923 Hot Metal Irons

The carry distances were good, with the lower-spinning Hot Metal Pro coming out as longer and producing more ball speed than the standard Hot Metal. This was the iron that was most similar to my own and I think the slightly smaller sole just gave me more confidence to strike down through the ball with a bit more commitment.

Out on the course, the main takeaway I had from these irons was just how versatile and easy to hit they were, no matter the lie the ball just seemed to pop up in the air with ease and provide me with pretty effortless distance. The irons were particularly good from the rough, performing almost as well from the long grass as from the fairway.

Mizuno JPX923 Hot Metal Irons

Despite the fact that the spin rates were low when testing on the launch monitor, I actually found that the stopping distances were pretty good because the ball launches high so it comes down at a nice steep angle.

As you do start to move from mid to long irons you do start to see a little bit of offset which helped to produce a consistent draw shape with these irons. The long irons felt extremely easy to hit with great turf interaction and a friendly look at address.

Mizuno JPX923 Hot Metal Irons Verdict

With the release of the JPX923 range Mizuno have widened the number of options for golfers when it comes to choosing an iron model that best suits them, although to be honest I think having three different Hot Metal options, as well as the JPX923 Forged and JPX923 Tour is a little bit confusing. That's before you even get to the Mizuno Pro range - there's three of those aswell!

Mizuno JPX923 Hot Metal Irons

Personally I think eight different iron models is a bit overkill from Mizuno, and you're bound to get some overlap between some of the models as a result. Yes, it might make things slightly easier when it comes to combo sets, but apart from that I don't really see the benefit.

But if you want Mizuno irons but still want game-improvement performance without having to sacrifice on distance and forgiveness, these could be right up your street. The standard Hot Metal and the Hot Metal HL are £135 per iron which is actually not bad value for money either, especially when you compare it with other brands on the market in this category.

Who Are They Aimed At?

Whilst these irons would be classed as 'game improvement' I think the Hot Metal Pro irons are not far off being 'players distance' as they have a sleeker look whilst retaining great performance. If you want to play Mizuno irons but you're worried that you're not good enough, the Hot Metals are the irons for you.

Would I Use Them?

Mizuno JPX923 Hot Metal Irons

They're not for me, but they're a great option for golfers looking for a set of irons which are really forgiving to hit and give you distance without having to work too hard for it.

Mizuno JPX923 Hot Metal Irons

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Golfalot Rating: 4 stars
More from Mizuno


Mizuno JPX923 Hot Metal Iron

Mizuno JPX923 Hot Metal Irons - Product Details

UK LaunchFebruary 2023
UK Launch RRP£945
European LaunchFebruary 2023
European Launch RRP€1225
Handicap Range
Hand AvailabilityLeft, Right
DesignCavity Back
Set Makeup4, 5, 6, 7, 8, 9, PW
Additional ClubsGW, SW
Manufacturer's WebsiteMizuno Website

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