Send your ball to Deep Space: The Mizuno JPX 925 Hot Metal HL iron Review

Mizuno’s latest Hot Metal series is boasting some serious ball speeds and more height than ever. But what if that’s not enough? Mizuno has more to offer.

With how well the previous generation of JPX 923 performed, especially for golfers looking at game-improver irons, it seemed like an impossible task for Mizuno to produce a better piece of equipment. With the release of the 925 Hot Metal series, we’ve seen a different approach.

The commitments that Mizuno made for designing the 925 Hot Metal range had two keys to it; they needed to retain the speeds attained with the 923 range, and they wanted to help lift the ball flight to elevate the new irons up past what was already available on the market. The speed element was already there so there was natural carryover of technology and material from the previous range, but improving on height is a harder ask. Luckily, Mizuno has a couple of solutions ready to help improve your game.

Aiming for new heights

For the construction of the Hot Metal HL, Mizuno have used both the traditional and the non-traditional to achieve higher flights.

Let’s look at the easiest way of gaining height with the traditional method. The HL irons are 3º weaker on each club than the standard Hot Metal and Hot Metal Pro equivalents, meaning you’re going to automatically see more of an upward trajectory with every club in comparison. This is ideal for some golfers because if there’s not enough speed in your swing for the loft in your hand, you aren’t going to get the ball high enough in the air to achieve either the right landing angle, so the ball can stop on the greens, or the correct launch angle to maximize your swing speed’s potential.

The downside of more loft is that the ball will increase in its spin – great for the height, not so good for distance.

The non-traditional height gain, and where the engineers at Mizuno have been really clever, is with a design that helps maintain distance, pushes launch higher, and keeps spin down.

Multi-Material Construction, used for the first time in the JPX series with 925 and brought over from the Mizuno Pro series, uses Nickel Tungsten custom weighting low down in the rear of the head. The tungsten pulls the Center of Gravity (CG) lower down into the head. Low CG has a positive influence on the launch of a golf ball as well as helping stabilize strikes that come out the bottom of the head. Mizuno has also moved to a new Contour Ellipse internal thickness design and Seamless Cup Face tech, to further retain height by protecting ball speeds in common miss areas.

All of these benefits come without a massive increase to the spin of the HL irons, or so the Japanese-owned company says.

Out on the course, I can certainly testify to the additional height, of these irons. I saw an improvement in my numbers with the standard JPX 925 Hot Metal, but nothing like I would with the HL. For my speed, the HL offers ludicrous amounts of height but this iron wasn’t designed for me; so I put these irons in the hands of some of my more average-speed playing partners to get their thoughts.

Golf, on easy mode

The overwhelming feedback is how easy these irons are to hit. There ultimately isn’t a substitute for more loft if you’re looking to increase the apex of your ball flight, but the decisions on weight placement have done a great job at keeping the flight moving forward as well as up, with extra spin kept in check. From observations of my own performance, as well as watching others, the height and spin combination means you barely have to think about what you want to do because the answer provided by the Hot Metal HL is always ‘long and straight.’

This, strangely enough, elicited a mixed response from the testing group. Some really enjoyed the performance, saying the iron made them feel great about their game even if they weren’t making perfect swings. One or two comments though, made an interesting point that I didn’t expect.

The feedback from some of the more accomplished golfers was that they didn’t feel like they could truly enjoy the set, as they felt it was making up for too much of their shortcomings and shots never seemed to be a reward for good play. A strange notion, but still one worth talking about.

I think the best way I can reconcile all these opinions is by making it simple. These are still game-improver irons. They’re designed for golfers who need some extra assistance and they do that job extremely well. But if you’re finding the center of the face more often than not, there are other offerings in Mizuno’s arsenal for you.

Good vibrations

With the reminder of what this iron ultimately is, I think this would be a good point to address one of the key pieces of feedback from any golf club – the sound.

Mizuno have used advanced geometry design and Acoustic Sound Ribs to improve feel by adding rigidity across sections of the top edge of the head. Coupled with the new Sound Bar (a visible piece of tech on the back of the club), which tunes sound pressure to remove clicky frequencies, Mizuno believes that it’s Harmonic Impact Technology – the net that all this design falls under – can help achieve feel and sound closer to a more player-orientated noise than a typical game-improver iron might.

For our group of testers and me, this may be the one failing of the 925 Hot Metal series. My impressions of the HL fall in with both the Hot Metal and Hot Metal Pro heads, with a question mark over the sound design.

For what Mizuno says, it’s still a louder, more powerful-sounding head, falling within the typical feedback style of a game-improver category iron. Had Mizuno not highlighted the acoustics as a reason to invest in this set, there’d be no need to point this out – but don’t go into a fitting for this head expecting a similar feel to their Pro line of heads.

That small niggle aside, this may be as easy as golf can be made. Height and distance combine in a good-looking yet simple shape that offers golfers an impressive overall package, and I’d have no issues putting this in the hands of any mid-handicap player who wants forgiveness, or an older golfer who’s looking to roll back a few years off of their game.

In the hands of our test pro

The previous Mizuno JPX923 Hot Metal HL could easily lay claim to having ignited the moderate speed iron category, as over the last two years the model introduced golfers to super swish looks in an area of the iron market where function traditionally wins out over form. This new replacement will hit a very similar spot.

The whole idea with HL irons is extra loft aids average swing speed players to hit shots higher (where less loft drives down, launch, spin, and descent angle) with more spin, so balls stay in the air for longer and hit the green and stop. You’re likely to need the tech if your swing speed hovers around or drops below 75mph with a 7-iron.

Our data shows the JPX925 delivers on its High Launch promise as shots launched higher, span more, flew higher, and hit the green at a steeper angle than the stronger lofted standard JPX925. At our test pros pace our numbers highlight the HL as the shortest iron within the three model JPX family (only by a couple of yards which is nothing when there’s 3° of loft difference), at more average speeds though any difference will swing in favor of the more lofted option.

The HL has 5.7 mm more blade length than the standard JPX925 so expect more of a midsize head, there’s also more hosel offset (about a millimeter) to position the center of gravity further back for easy launch and increased forgiveness.    

Data comparison: How the Mizuno JPX925, 925 Pro, and 925 HL irons compare in data (Test pro data)

Iron	7-Iron Loft	Ball Speed	Launch Angle	Backspin	Height	Descent Angle	Carry Distance	Shot Area
JPX925 Hot Metal Pro	28°	128.3 MPH	12.8°	5180 RPM	28 YDS	41.7°	189 YDS	330.4 SQ YDS
JPX925 Hot Metal	28°	127.4 MPH	13.2°	5357 RPM	28 YDS	42.2°	186 YDS	246.6 SQ YDS
JPX925 Hot Metal HL	31°	127.2 MPH	13.7°	5882 RPM	29 YDS	43.6°	184 YDS	295 SQ YDS

About the author

Lewis Daff

Lewis Daff joined the Today’s Golfer digital team in 2024, having spent more than a decade in both big box golf retail and independent stores, working as a club fitter and builder.

Experienced with every level of golfer, from beginner to professional, he has achieved Master Fitter and Builder status with most major manufacturers, including Mizuno, Taylormade, and Callaway, helping him to cement both a wide and deep knowledge base. Lewis specializes in Clubs, Shafts, Training Aids, Launch Monitors and Grips.

In Lewis’ bag is Titleist GT3 Driver (9º) with Fujikura Ventus Black, Titleist GT2 Fairway Wood (15º), Wilson Staff D9 Forged 3-iron, Srixon ZX7 MKii Irons (4-PW), Titleist SM9 Wedges (52º, 60º), Toulon San Diego Putter, and Callaway Chrome Tour Ball.

Talk to Lewis about why steel shafts are now dead and graphite is the only way forward or any other equipment you’d like to debate via his email.

Details: Mizuno JPX 925 Hot Metal HL Irons

RRP: £900 (6-piece set) Steel shafts, £150 per iron 

Availability: 4 – PW, GW, SW (RH Only)

Stock shafts: Nippon NS Pro 950 Neo (s) UST Mamiya Recoil Dart ESX (g)

Stock grips: Lamkin UT+

7-iron loft: 31°

Category: Game Improver Iron

Construction: Multi-Material Construction / Nickel Chromoly