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Mizuno · Pro Series
Mizuno Pro S-1 Irons – Grain Flow Forged HD Muscle Back
Pure muscle backs designed for players who demand ultimate precision and workability, Grain Flow Forged HD in Hiroshima, Japan.

Overview
Legacy reborn
The Mizuno Pro S-1 irons are pure muscle backs, designed for players who demand ultimate precision and workability. At the core of the S-1 is Mizuno’s Grain Flow Forged HD process, carefully executed in Hiroshima, Japan. Forged from a single billet of 1025E Pure Select Mild Carbon Steel, the S-1 delivers the soft and responsive feel through impact that Mizuno is known for, and a copper underlay subtly refines vibration patterns for the purest feedback.
Channel Back Design
Repositions mass behind the face for a more stable vertical CG and consistent launch conditions.
Tour-Tested Sole
A flatter camber, sharper leading edge and increased bounce for smoother turf interaction, especially for steeper swings.
Copper Underlay
A thin copper layer beneath the chrome softens vibration while keeping a crisp response.
Technology Highlights
Mizuno feel, refined
Grain Flow Forged HD
Forged from a single billet of 1025E Pure Select Mild Carbon Steel in Hiroshima, Japan, for a tighter grain structure and buttery-soft feel.
Harmonic Impact Technology
Works with the channel back geometry to fine-tune vibration for a slightly firmer, solid impact sensation.
Soft White Satin Finish
Nickel Chrome Soft White Satin reduces glare at address.
Specifications
Specifications
Manufacturer specifications. Swipe sideways on mobile to see all columns.
| Club | Loft | Lie | Offset | Length |
|---|---|---|---|---|
| 4 | 24° | 60.5° | 0.098" | 38.75" |
| 5 | 27° | 61° | 0.094" | 38.25" |
| 6 | 30° | 61.5° | 0.091" | 37.75" |
| 7 | 34° | 62° | 0.087" | 37.25" |
| 8 | 38° | 62.5° | 0.083" | 36.75" |
| 9 | 42° | 63° | 0.079" | 36.25" |
| PW | 46° | 63.5° | 0.075" | 35.75" |
- Set makeup: 4-PW
- Shaft options (this listing): KBS Tour Steel Stiff; Project X 6.0 Steel
- Dexterity (Mizuno): RH & LH 4-PW; this listing is right-handed
Specifications from https://mizunogolf.com/us/golf-clubs/mp-series/mizuno-pro-s1/; design specifications may vary.
Who It’s For
Who it’s for
- ✓Players who demand ultimate precision and workability
- ✓Golfers who want a pure muscle back
- ✓Soft, responsive forged feel
- ✓Consistent launch and turf interaction
FAQ
Frequently Asked Questions
Where are the S-1 irons forged?
Grain Flow Forged HD in Hiroshima, Japan, from a single billet of 1025E Pure Select Mild Carbon Steel.
What does the channel back do?
It repositions mass behind the face for a more stable vertical CG and consistent launch, with a firmer, tour-preferred feel.
What is the set makeup?
4-PW.
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📦 How to Start a Return
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