Mizuno JPX 921 Forged Vs. Mizuno MP-20 HMB Irons Review 2023

If you have ever played a Mizuno iron, any Mizuno iron, you already know that the manufacturer emphasizes quality construction materials and outstanding feel.

Indeed, that is precisely what you get with the Mizuno JPX921 and the MP-20 HMB irons. However, there are some key differences between these two set. If you have the money to splurge on either of these iron sets you should know all the facts before you make a decision.

In the following article we will give you the background for both of these sets and share with you the results of our side-by-side testing.

Mizuno JPX921 Forged Irons Overview

The Mizuno JPX921 Forged irons were released in September of 2020 and they immediately fell in line with the rich heritage of past Mizuno models.

One of the things that makes Mizuno such a renowned name in golf is their grain flow forging. Grain flow forging follows the natural pattern of the solid piece of metal. It doesn’t detract from the strength of the metal but actually reinforces it by going along a uniform grain pattern.

The Mizuno JPX921 Forged irons feature this process of forging as do many previous and subsequent Mizuno models.

Mizuno MP-20 HMB Irons Overview

The Mizuno MP-20 HMB irons actually came out before the JPX921’s. They were released in the fall of 2019.

The Mizuno MP-20 HMB irons were designed as an innovative set of hybrid irons. They took the idea of replacing the longer irons with hybrids and followed it through the entire set.

Mizuno JPX921 Forged Irons Key Features

The JPX921 irons couple incredibly sleek looks with an amazing forged feel.

The Mizuno JPX921 Forged irons have a beveled trailing edge on the sole which smooths out turf interaction. This coupled with the obvious amazing feel from the grain flow forging process makes these irons so pleasing to swing.

The blades of these muscle back irons are pretty compact and there is a part of the back area that has been milled to increase stability and thin out the back wall a bit. These irons also feature the notorious  chromoly construction which contributes to the soft feel.

Mizuno MP-20 HMB Irons Key Features

We were excited to see an adjustable hosel in what is essentially meant to be an entry-level PXG driver (if such a thing exists).

After the first swing, we were taken aback at how soft and smooth this driver felt. We credit this to the railed sole design which increase MOI but also adds stability by bracing the heel and toe.

The honeycombed polymer insert in the head doesn’t hurt either. Plus, the fact that you can shape shots better with the adjustable hosel actually makes this driver a great value.

Who is Each Set Best for?

For starters, both of these iron sets would work great for any player who wants to emphasize precise feedback and feel.

Let’s just start by saying you’re not going to want to invest in these irons if you’re just starting out with golf. These are performance irons through and through. While the JPX921 Forged irons do give impressive distance the compact heads and points of design emphasis will be lost on beginners.

Instead, both of these iron sets would be most beneficial for mid to low handicappers looking for more performance from their scoring irons.

The JPX921 Family

The JPX921 Forged irons are joined by the JPX921 Tour and JPX921 Hot Metal irons.

The JPX921 Tour irons produce surprisingly straight shots for tour-grade clubs. They have sleek, compact heads and feature the same grain flow forging construction. The JPX921 Hot Metal irons are the most forgiving in the family with a Cup Face design that preserves ball speed around the perimeter.

The MP-20 Family

The Mizuno MP-20 line of irons also includes the standard MP-20 and the MP-20 MMC irons.

The Mizuno MP-20’s are your straightforward muscle back irons. They were forged from a single piece of mild carbon steel which lends incredible stability and feel to these irons. The MP-20 MMC irons feature a hybrid cavity/muscle back design.

This design helps make these the more forgiving irons in the family. They play straight and longer than normal on off-center strikes.

Loft Comparison
Mizuno MP-20 HMB LoftMizuno JPX921 Forged Loft
2 IronN/A16
3 IronN/A19
4 Iron2122
5 Iron2425
6 Iron2728
7 Iron3132
8 Iron3536
9 Iron4041

Mizuno MP-20 HMB Options

  • Aerotech Steelfiber i110 Graphite shaft
  • KBS $-Taper Black PVD Steel shaft
  • KBS $-Taper Chrome Steel shaft
  • KBS $-Taper Lite Black PVD Steel shaft
  • KBS C-Taper Lite Steel shaft
  • KBS Tour Steel shaft
  • Stiff, regular, extra stiff flex

Mizuno JPX921 Forged Options

  • Aerotech Steelfiber i110 Graphite shaft
  • UST Mamiya Recoil ESX Graphite shaft
  • True Temper Project X Steel shaft
  • True Temper Project X LS Steel shaft
  • True Temper Dynamic Gold Steel shaft
  • Nippon N.S. Pro Modus Tour 125 Steel shaft
Length & Lie Comparison
Mizuno JPX921 Forged Lie/LengthMizuno MP-20 HMB Lie/Length
2 IronN/A59/39.5

3 IronN/A59.5/39
4 Iron60/38.560/38.5
5 Iron60.5/3860.5/38
6 Iron61/37.561/37.5
7 Iron61.5/3761.5/37
8 Iron62/36.562/36.5
9 Iron62.5/3662.5/36

Performance & Composition Comparison

The Mizuno MP-20 HMB irons had the softer feel between these two irons sets – probably because they were forged from carbon steel. However, the JPX921 irons did play more accurate around the pin and were more forgiving with their toe bias weighting.

Price Comparison

  • Mizuno MP-20 HMB – $1400
  • Mizuno JPX921 Forged – $1400

Mizuno JPX921 Pros & Cons


  • Good accuracy
  • Forgiving
  • Played longer
  • Great feedback
  • Toe bias
  • Milled back


  • Pricey
  • Heavy
  • Fewer long iron options
  • Not for beginners

Mizuno MP-20 HMB Pros & Cons


  • Amazing feel
  • Great scoring irons
  • Layered face
  • Wide sole
  • Chromoly design
  • Brushed finish


  • Not as accurate
  • Not for beginners
  • Pricey
  • Heel bias

Final Assessment

We really liked the short game accuracy of the JPX921’s. While both of these irons felt amazing, you get more of everything from the JPX921’s: distance, forgiveness and accuracy. They are our pick so check out the Mizuno JPX921 Forged irons today!