Mizuno MP-20 HMB irons with forged Chromoly material

By: September 27, 2019

One of the things I like in writing about new golf clubs is how manufacturers are trying to find new materials to improve performance.

This is also true regarding the latest Mizuno MP-20 HMB irons. In the last couple of years, many brands adopted the usage of tungsten.

Mizuno MP-20 HMB irons 2019

The Mizuno MP-20 HMB irons are a new breed of hollow-headed ‘Hybrid Muscle Back’ in a tour-ready profile that features Mizuno’s forged Chromoly material in the face and neck.

It is inspired by the proliferation of long iron replacements on tour but extends the concept right down to the wedges.

It also features copper-plating within the heads to add ‘layers of feel’ at impact.

What is Chromoly steel? Do we really need it?

It is a type of low alloy steel. The name is a combination of word “chromium” and molybdenum”. They are the two of the major alloying elements.

Chromoly steel is often used when more strength is required than that of mild carbon steel. The drawback of it is the price.

To understand the strength of this material:

  • Chromoly has a 97,000 pound/inch of tensile strength;
  • Hi-ten steel has a 61,500 pound/inch of tensile strength.

Chromoly steel is also the preferred steel among BMX bikers. So for the sake of performance and durability it is worth spending a little bit more…

Mizuno MP-20 HMB irons – technical details

Mizuno used the chromoly material in the face and neck of the Mizuno MP-20 HMB irons. It is supported by a precision stainless steel body and tungsten weighting.

It offers the proportions, topline and offset transition of a classic Mizuno players’ muscleback with a generous sole width that’s hidden at address.

Mizuno MP-20 HMB irons are designed to help consistent players pursuing added ball speed without sacrificing their shot-making options.

The heads feature a brush satin durable plated finish and a complex, loft-specific construction:

  • From 2- to 8-iron, Mizuno’s multi-thickness Grain Flow Forged Chromoly face and neck is dialled in to be consistently hot across the clubface.
  • From 2- to 7-iron, twin 12g tungsten weights deliver stability and an easy launch, while use of a softer 1025E Pure Select mild carbon steel from 9-iron to PW makes the short irons soft and responsive.

Mizuno MP-20 HMB irons are designed to be played as a full set or mixed with any MP-20 set, with recommended break points between the 4- and 5-iron or 7- and 8-iron for blended sets.

Availability of Mizuno MP-20 HMB irons

  • RH #2-PW;
  • LH #3 – #4 iron (as a split set with 5-PW MP-20 MB)