Mizuno JPX-850 Forged Irons Review

Mizuno has brought to market a great set of clubs this year, the JPX-850 Forged irons. Typically Mizuno uses 1025E steel in their forging process but this year they incorporated 1025 Boron, which is a stronger metal allowing the iron face to be forged thinner for more distance and forgiveness. The JPX-850 Forged features the “Power Frame Technology,” creating a larger sweet spot without making the club head any bigger.



From Mizuno:

After six years of development - the introduction of BORON to Mizuno's Grain Flow Forging process allows the JPX-850 Forged to overcome the distance limitations of traditional forged irons.
Mizuno's new material is 30% stronger than traditional 1025E steel billets - allowing for a thinner face and extreme ball speeds. The result is an incredible iron that combines Grain Flow Forged precision and feel with shocking distance. A combination that was unachievable before BORON.

This new, thinner face is strategically reinforced by a Power Frame cavity which places weight to the extreme corners of the club head for maximum forgiveness along with increased distance. A clean, sleek design combined with these breakthrough technologies delivers an iron that looks and plays like nothing before.

Mizuno has long used the proprietary 1025E steel along with their Grain Flow Forging to get that sweet soft feel at impact that most crave. With the addition of boron, this allows Mizuno to thin out the face, thus giving the club a more trampoline effect at impact.

The process of creating the JPX-85- forged irons is the same process as the MP’s. The “Power Frame Cavity” design moves material to the outer edges of the head allowing for a deeper cavity back iron while still being a forged iron.

Tech Specs:

  • Grain Flow Forged 1025 BORON: 30% stronger material for thinner face and longer distance while delivering soft, solid, consistent feel.
  • Power Frame: Enables entire face to flex for increased ball speeds and distance.
  • Ultra CNC Milled Pocket: Higher launch angle and increased ball speeds in 4 through 7 irons.


The new JPX-850 forged irons have a clean and crisp look straight out of the box. The simple but yet subtle cavity badge with minimal color allows for the club to speak for itself. A lot of game improving irons can get over carried with the badging and look of their clubs, not Mizuno. The badging has clear cut lines and stands bold in silver and black. The sole and surround of the club has a satin yet polished finish to it. When at address, the top line is much thinner than the older JPX irons which reminds me more of the MP models.

The clubs that Mizuno sent GolfBalled.com were 4-GW with a True Temper ZP-115 stock shaft and standard grips. The stock grip is similar to a tour velvet grip and works great for most but I did not like the feel of them. I choose to switch to a tour wrap style grip for this testing.


I have hit the older JPX EZ clubs before and have always been a fan of Mizuno. The JPX-850 forged are more forgiving than the MP irons, however when you hit the ball off center, you feel it right away. Playing with these clubs for the past 4 rounds, I have grown to hit these better than my TM’s. When struck dead on, the ball popped off the face with ease and you can feel when you hit that pure shot that you intended to hit. With the stock XP-115 shafts, I felt that the ball flight was a little higher than I wanted but this can be changed easily with a re-shaft. Throughout my testing I was impressed with the overall forgiveness the JPX-850 forged irons. Being that they are forged I expected much less forgiveness. Who’s not to say I didn’t have a few shots that I shanked into the woods or into a bunker, that’s normal. I’m no pro, but these clubs felt great.

Although I am getting older, I did see some yardage gains in my 5-9 irons with these clubs. The 4 iron I have not been able to hit very well and I feel that I can’t find the sweet spot most of the time. However, Mizuno does make some great hybrids to fill in for those 3 and 4 irons. For PW and GW I did not see much distance gain or more control but they are solid hitters.

In closing, I wasn’t much a believer in the addition of boron to the forging process to improve these clubs but I am a believer now. The team at Mizuno has done an awesome job with the JPX-850 forged irons. These are a great addition to their lineup and a set that is perfect for those 6-16 handicappers. If you are looking for an iron set that moves you closer to a players iron or just want to step up your game a little, these are a must try.

The JPX-850 forged irons retail for $999.99 for 4-GW. Check out Mizuno’s website for more details on these and much more at, http://www.mizunousa.com/golf