What you need to know: Mizuno is launching the successor to its JPX921 series. Engineers leveraged the company’s custom-fitting program — including data from 350,000 golfers — in the creation of the JPX923 series, which includes five models: JPX923 Tour featuring a new V-Chassis and thinner topline, JPX923 Forged with features Mizuno’s third generation of chromoly forging, JPX923 Hot Metal, JPX923 Hot Metal Pro, and JPX Hot Metal HL all featuring new, faster 4335 nickel chromoly, which is 35 percent stronger than Mizuno’s original chromoly.

Mizuno JPX923 irons: What’s new, key technology

JPX923 Tour

Featuring a copper underlay for “Mizuno feel,” the JPX923 Tour is one-piece Grain Flow Forged in Hiroshima Japan from 1025E Pure Select mild carbon steel. Narrower top line and sole in tandem, more rounded trailing edge for cleaner turf interaction.  Features Mizuno’s new ‘V-Chassis’.

“The goal was to engineer a compact, players cavity back that looked and felt like a muscleback at impact. With the copper underlay and new topline, the JPX923 Tour is right there,” says David Llewellyn.

JPX923 Forged

Mizuno’s third-generation of chromoly forging places a wider milling slot heel to toe in the 4120 chromoly 4 through 7-irons as well as well as a thinner clubface. JPX923 Forged are mid-sized, full body Grain Flow Forged irons with a thinner topline and bevelled sole throughout. The scoring irons (8-GW) also feature more compact design and are forged from 1025E Pure Select mild carbon steel.

“The new JPX923 Forged pulls off two impressive achievements. First it feels more solid even though it’s faster from the face. Second, it looks sleeker with a thinner topline and narrower sole even though it plays more forgiving,” says Chris Voshall, Mizuno’s Director of Product.

JPX923 Hot Metal, Hot Metal Pro, Hot Metal HL

With the JPX923 Hot Metal, Mizuno introduces “4355 nickel chromoly,” which is 35 percent stronger than the original Hot Metal material and allows for an eight-percent thinner clubface. Cup face construction works in tandem with a deep center of gravity for high launch with stopping power.

Mizuno developed Hot Metal Pro, Hot Metal and Hot Metal HL (High Launch) from 175,000 real golf swings recorded via Mizuno’s Swing DNA system and describes the three models as follows.

• JPX923 Hot Metal Pro is a player’s speed cavity that’s compact, with minimal offset for confident ball-strikers seeking maximum ball speed. It’s suitable for low to mid handicap golfers.
• JPX923 Hot Metal is a forgiving speed cavity suitable for mid to high handicap golfers. It features a full speed, high stability cavity for straight flight and distance.
• JPX923 Hot Metal HL is a high launch speed cavity delivering a higher launching option for players with moderate swing speeds or aggressive shaft lean, it’s suitable for mid to high handicap golfers.

What Mizuno says

“The new JPX923 series was planned out with Mizuno’s custom ethos at its core” says David Llewellyn, Director of R&D for Mizuno. “We already offer more than 50 unique shafts within our custom program, by expanding to five iron models, there’s an ideal combination for every type of player.”

“We’re constantly evolving the JPX series based on more than 175,000 unique swings we capture every year on the Mizuno Shaft Optimizer,” says Bill Price, Mizuno’s Director of Fitting. “Recently we’re seeing an increase in the number of players with slightly slower swing speeds being fitted – and a trend to more shaft lean. Hence a slight increase in bounce angles through all the models and the introduction of the Hot Metal High Launch.”

Resident Club Junkie Brian Knudson’s take

Note: GolfWRX has not yet gotten an in-hand look at the JPX923 Tour or Forged irons. 

Mizuno’s Hot Metal HL irons look easy to hit and high flying with their larger sole and longer heel to toe shape. You can see some of the tech that is packed into these irons around the badge like the Harmonic Impact ribs and the Stability Frame. Like you would expect from Mizuno the finish quality and badging all look very good and catch your eye without the need for wild colors.

The Mizuno Hot Metal irons look to be the bread and butter of the lineup. The Hot Metal features a little smaller footprint than the HL, less offset, thinner top line, and narrower sole. The look from address will please most golfers and it is still packed with the technology for easy distance and effortless launch.

Hot Metal Pro irons are the smallest of the three but should still offer a great combination of looks and performance. They are still a little longer from heel to toe while offering the least offset and thinnest toppling of the group. The short irons are shaped really well and the whole set flows great from 4 iron down to the pitching wedge.

What they look like

JPX923 Hot Metal Pro

Mizuno JPX923 Hot Metal

JPX923 Hot Metal HL

Pricing and availability

JPX923 Hot Metal Pro: 4-PW RH and LH
JPX923 Hot Metal: 4-LW RH and LH
JPX923 Hot Metal HL: 5-SW RH only

Tour, Forged will hit retail in February of 2023. Hot Metal models at retail late September.

• JPX923 Tour/Forged – $187.50 per club
• JPX923 Hot Metal/Hot Metal Pro/Hot Metal High Launch – $137.50 per club

Loft comparisons to JPX921