Equipment
Mizuno JPX-900 Hot Metal and JPX-900 Forged irons
Along with the company’s new JPX-900 Tour irons, Mizuno will also launch its new JPX-900 Hot Metal and JPX-900 Forged irons, which will replace the JPX-850 and JPX-850 Forged irons.
Unlike Mizuno’s MP irons, which are blade and blade-like irons designed for better players, the JPX line of irons are designed to offer golfers more forgiveness and distance, packaged into slightly larger head sizes. Think of them as “tweener irons,” according to David Llewellyn, Mizuno’s Director of R&D.
As is expected from the JPX line, the new crop of JPX-900 Forged and Hot Metal irons focuses on playability and distance, but doesn’t ignore feel and sound in the design process. To accomplish the feat, each of the new offerings use special materials. The JPX-900 Forged irons are made with a special 1025E Grain Flow Forged steel that is infused with boron. The JPX-900 Hot Metal irons are cast from a metal called Chromoly 4140M, which you can learn more about below.
JPX-900 Forged irons
Along with being larger than Mizuno’s new JPX-900 Tour irons, the JPX-900 Forged irons have a chemical trick up their sleeves to offer greater forgiveness and more distance — a material called boron.
The company began using boron with its JPX-850 Forged irons, although two years after their release there is still lingering confusion among golfers as to how and why boron is actually used. Contrary to popular belief, boron is not used as a replacement for traditional steel in the design. Rather, a small amount of boron (30 parts per million, according to Mizuno) is mixed with the company’s Grain Flow Flowed 1025E steel to increase strength. This allows Mizuno to forge the faces of boron-infused thinner, leading to faster ball speeds without sacrificing durability.
Mizuno started experimenting with boron after seeing its success in the auto industry, where the material helped create auto parts with a higher strength-to-weight ratio to make stronger, more more fuel-efficient structures. Mizuno found that it translated well into iron making, helping them offer better distance and consistency. The difficult part about using boron, according to Llewelyn, was getting the mixture right so that the company’s irons would maintain their signature sound and feel.
“It took 5 years to figure out how to do it,” Llewelyn said.
The JPX-900 Forged irons, therefore, are the second-generation of JPX irons to use boron. To make the irons longer and more forgiving than their predecessors, Mizuno reshaped the pocket cavity of the irons to create a larger rebound area, giving them faster ball speeds on off-center hits.
Head sizing throughout the set has also changed; the longer irons have a longer blade length, while the shorter irons have a more compact look, with the “crossover” being at the 6-iron.
The JPX-900 Forged ($1200) come stock with True Temper’s Project X LZ shaft, and will hit stores Sept. 16.
JPX-900 Hot Metal irons
In the new age of iron design, companies search for ways to make the faces thinner in order to produce faster, more consistent ball speeds. That’s how Mizuno stumbled upon 4140M Chromoly, a common scientific name for the mixture of chromium and molybdenum. Mizuno found that the material, which is used in aircraft tubing, firearm parts, bicycle frames and race car roll cages, had a two-fold benefit in iron design.
The way Mizuno heat treats the Chromoly allows the irons to be built with thinner and stronger faces, while still maintaining their bendable, loft-and-lie adjustable hosels. If you’ve equipment articles on GolfWRX in the past few years, we’re quite keen on the benefits of custom-fitting when making a club purchase, so this puts a smile on our face.
The Hot Metal irons also have a “cup face,” which makes the faces thinner and more flexible. What’s unique about Mizuno’s cup-face design is that it is created without the usual face weld. That works to raise coefficient of restitution (COR) to 0.828, according to Mizuno, just shy of the USGA’s legal limit.
The JPX-900 irons are also equipped with a triple-cut sole for better turf interaction from a variety of lies and “sound ribs” behind the top cavity for improved acoustics. The ribs are similar to what are used in metal woods, where they quiet the vibrations to improve the feel of the hollow, thin-faced clubs.
For golfers who prefer to purchase wedges that match their irons, Mizuno redesigned the JPX-900 Hot Metal wedges to maximize performance around their greens. The set’s gap, sand and lob wedges are made from X30 Stainless Steel — a soft and bendable material, according to Mizuno — with head shapes that are inspired by the company’s S5 wedges. Like Mizuno’s premium S5 and T7 wedges, the Hot metal uses the company’s Quad-Cut grooves for improve spin control, and the sole grinds are progressively shaped to suit the respective purposes of each loft.
Related: Click to See photos of Mizuno’s new wedges
JPX-900 Hot Metal sets (4-PW, GW) will come stock with Nippon N.S. Pro Modus3 Tour 105 steel shafts, and will hit stores on Sept. 16 for $900.
Related: See what GolfWRX members are saying about the clubs in our forums
Neal Shipley was the first to admit that he enjoyed his food while in college. But since his days at Ohio State, he’s slimmed down and earned a PGA Tour Card.
That hasn’t stopped him from having fun with his wedge stampings, though it’s led to some misunderstandings.
On the 54 (degree), we have ‘Big Fudge,'” Shipley told GolfWRX. “It was supposed to be ‘Big Fridge,’ so this happened a little while ago. ‘Big Fridge’ was a nickname between my college teammates and I, with ‘fridge’ meaning stomach, a big stomach.
“We told the Ping guys to put … ‘Big Fridge’ on it, and I think maybe some bad cell service or something, and they thought I said ‘fudge,’ so they put fudge on it.”
On Shipley’s 50-degree he also continues the food theme, this time with his go-to order at the “Golden Arches,” and his stamping “DONS 7.”
“The number 7 meal, the two cheeseburger meal, that was my McDonald’s order, back when I would have McDonald’s frequently,” Shipley shared.
At GolfWRX, we are a community of like-minded individuals who all experience and express our enjoyment of the game in many ways.
It’s that sense of community that drives day-to-day interactions in the forums on topics that range from best driver to what marker you use to mark your ball. It even allows us to share another thing we all love – buying and selling equipment.
Currently, in our GolfWRX buy/sell/trade (BST) forum, @raw10628 has a L.A.B. DF3 putter and Masters putter cover up for grabs.
From the listing: “Some great items here today, time to thin out and make room for next set of gear. All prices include shipping.
LAB DF3 Purple 33.5” 68° lie with TPT – $725. LAB Masters release DF3 cover – $150.”
To check out the full listing in our BST forum, head through the link. If you are curious about the rules to participate in the BST Forum, you can learn more here: GolfWRX BST Rules
Driver: Ping G440 LST (9 degrees)
Shaft: Accra TourZ Green 5-M4
3-wood: Ping G440 Max (15 degrees)
Shaft: Accra TourZ Green 6-M4
5-wood: Ping G440 Max (19 degrees @18)
Shaft: Accra TourZ Green 6-M4
Hybrid: Ping G440 (23 degrees)
Shaft: Oban Isawa Red Hybrid Shaft 04 Flex 70 Gms
Irons: Srixon ZXi7 (5-P)
Shafts: Aerotech SteelFiber Private Reserve i80
Wedges: Cleveland RTZ (50-MID, 54-FULL, 58-MID)
Shafts: Aerotech SteelFiber Private Reserve i105
Putter: L.A.B. Golf OZ.1i
Shaft: ACCRA Putter Shaft
Grips: Golf Pride Tour Velvet
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Maria Torres WITB 2026 (June)
Driver: Ping G440 LST (9 degrees) Shaft: Accra TourZ Green 5-M4 3-wood: Ping G440 Max (15 degrees) Shaft: Accra TourZ Green 6-M4 5-wood: Ping G440...
Eric Cole WITB 2026 (June)
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Driver: TaylorMade Qi4D (10.5 degrees) Shaft: Project X Titan Yellow 60 TX 3-wood: TaylorMade Qi4D Tour (15 degrees) Shaft: Project...
RAT
Sep 15, 2016 at 8:10 pm
I LIKE THE LOOKS AND WOULD CONSIDER BUYING THEM . BUT THE PRICE IS TOO HIGH !! THAT’S THE PROBLEM WITH GOLF IT’S NOT REASONABLE PRICED !! THE FEWER THAT PLAY, THE COST GOES UP.THAT’S NOT THE WAY TO BRING IN NEW GOLFERS. DROP THE PRICE OF EQUIPMENT ,PLEASE,PLEASE… YOU WILL SEE MORE GETTING INTO GOLF. IT COST TOO MUCH!!!!!
Dutzow
Aug 30, 2016 at 2:05 am
Have the callway x2hots which I really enjoy. I don’t love the look however, and most of their recent offerings have looked even worse. Really enjoy the look of these though! Glad someone made an iron that wasn’t obnoxious!!
Bert
Aug 19, 2016 at 7:49 pm
Development may create costs but excessive cost create loss of sales. The industry needs a better price point. I just passed on Callaway Apex irons, yes like I them, but just can’t justify the extra cost for a “distance” change.
mr b
Aug 18, 2016 at 12:09 pm
did someone from mizuno beat your a$$ or something? you sure do have an inferiority complex for them
mr b
Aug 18, 2016 at 4:16 pm
same here. inferiority complex it is.
5kywalker
Aug 19, 2016 at 1:46 am
Smizzle, you seem to be the only one here with such a harsh view on these clubs. In essence, you just sound mental.
So please pipe down whilst the adults talk.
There’s a good lad.
Brian
Aug 17, 2016 at 1:53 pm
You have to be the least capable internet troll I’ve ever run across.
Mark Walgren
Aug 22, 2016 at 2:07 am
Oh come on. A very bold statement such as your original comment is bait. Explain yourself. Why do you say they steal so much?
Nolanski
Aug 22, 2016 at 12:31 pm
He’s been trolling hard for awhile now. Its best to just ignore him.
James Bond
Aug 17, 2016 at 9:17 am
Just stop.
Pub
Aug 17, 2016 at 10:38 pm
He was talking to you, varmint
Uncle Buck
Aug 17, 2016 at 4:24 am
Chromoly?? In the 70’s I had a bmx bike frame made of that! Next we’ll be wearing Angels Flight golf clothing and platform Farmalari’s!!
Pub
Aug 17, 2016 at 3:20 am
You didn’t. Nobody cares what you say, you’re just a pathetic varmint
KK
Aug 16, 2016 at 11:21 pm
Seems like great tech but I’m not sure anyone can match what Titleist has done with AP2, T-Mb and C16.
Leon
Aug 16, 2016 at 7:24 pm
Nothing particular innovative here. Just appearance change and minor tuning. The JPX 800 and 850 are all have 0.83 COR already, so no distance increase at all.
The only good part is the stock Project LZ shafts, which are better shafts than the crap DG S300, but they add the up charge into the total price. $1200 for a new set? Give me a break (it was $799, then $899, then $999, and now we have $1200, good for everybody)
Tom
Aug 16, 2016 at 11:23 pm
“Mizuno started experimenting with boron after seeing its success in the auto industry, where the material helped create auto parts with a higher strength-to-weight ratio to make stronger, more more fuel-efficient structures. Mizuno found that it translated well into iron making, helping them offer better distance and consistency. The difficult part about using boron, according to Llewelyn, was getting the mixture right so that the company’s irons would maintain their signature sound and feel.” That type of research and technology cost’s money.
Leon
Aug 17, 2016 at 10:55 am
The “boron” thing is more like minor tuning. The JPX 800 and later 850 (not pro version) cast steel iron have all reached the 0.83 COR upper limit with “ultra thin face”. The boron may make the face thinner but the elasticity is constrained to the 0.83 limit, so whether the face is thinner or thicker, as long as the COR is 0.83, the overall distance will be pretty much the same, no matter what materials they are using.
I like Mizuno’s club and am playing the MP 69 blades. The new irons look good, but performance wise, as long as you have been properly fitted, there is really no difference between newer or elder models.
Pub
Aug 17, 2016 at 3:17 am
They’re only matching everybody else’s prices. Not a big deal. It’s the state of things now.
doesnotno
Aug 17, 2016 at 8:43 am
“the crap DG S300”
Yup, there’s a shaft that will never catch on.
Brian
Aug 17, 2016 at 1:52 pm
Too bad the DG S300 wasn’t the stock shaft in the 850s.
Justin
Aug 16, 2016 at 5:55 pm
Is it just me or is does the new price for a set of irons seem to be around $1,200??? $999 was bad enough but now it’ll cost the average golfer about $2,640 for a full set excluding putter ($1200 irons, $500 driver, $300 3-wood, $250 hybrid, $130 wedge x3). I guess very few people go out and buy brand new everything all at once, but this pricing seems more and more outrageous each year.
Pub
Aug 17, 2016 at 3:19 am
Yeah it’s because they’re all offering so many kinds of shafts included in the price now, unlike 2 years ago when most of those were all uncharged to this price from the basic shaft option price. We’ve come a long way in getting so many shafts included in the one price
Steve
Aug 16, 2016 at 4:10 pm
Looks like the OEM’s are catching onto Hi-COR irons like Wishon did years ago.
golfraven
Aug 16, 2016 at 3:21 pm
Mizuno are building some great looking sets in recent seasons – worth considering.
Tom
Aug 16, 2016 at 1:33 pm
chromoly I like the sound of that. Sir 138 carries..you have 145 to the center ….Hand me my chromoly 9 iron……
Ryan
Aug 16, 2016 at 1:18 pm
Does this mean that Mizuno will no longer offer no up charge custom shafts? That was a big selling point for them this year.
Brian
Aug 16, 2016 at 3:06 pm
It seems that they’re hiding the upcharge in the base price
Chris
Aug 16, 2016 at 6:28 pm
Right. Still no upcharge shafts, but they included Recoil Graphite in at $900 as well as the steel prices so no more Orochi. It’s Recoil and PX Loading Zone for graphite. Chromoly’s are stupid long, too.
sumsum
Aug 17, 2016 at 7:37 am
Except they were the first to offer no upcharge shafts, so they aren’t baking it into the price, this is just the market now. At least Mizuno technology is reflective of actual innovative work that takes time and resources to develop new constructions and usage, like chromoly and boron. Development creates cost.