Meanwhile, the first two offerings in the new Mizuno Pro Signature Series<\/a>, the S-1<\/a> and S-3<\/a>, were a compact blade and a compact shallow cavity. Irons designed for elite ball strikers, but not as much for a player who wanted just a touch of forgiveness.<\/p>\n But now the company is adding to the Signature Series with the new Pro S-4<\/a>, the largest and most forgiving cavity-back option in the lineup made up of all single-piece Grain Flow forged irons.<\/p>\n \u201cThe S-4 is a more forgiving, slightly larger, slightly more offset version of Mizuno Pro,\u201d Mizuno Director of Golf Chris Voshall told GOLF. \u201cWhich all sound like things that are not Mizuno Pro. But it\u2019s just very slight tweaks in all of those things.\u201d<\/p>\n Keep reading below for more on the Mizuno Pro S-4 irons<\/a>, including my take on the release.<\/p>\n What\u2019s actually new with Mizuno Pro S-4 irons \u2014 and why you should careFilling the cavity-back-sized hole<\/p>\n Mizuno branched off its Mizuno Pro line into the Signature Series \u2014 single-piece forgings for players who demand feel above all \u2014 and the Modern Series \u2014 for players who want Mizuno Pro feel, but want the speed boost from modern tech too.<\/p>\n While the S-1 and S-3 catered to the elite ball strikers, and M-13 and M-15 were for players seeking more distance<\/a>, the S-4 is for the player in the middle: Players who want feel and forgiveness but don\u2019t need extra speed. It\u2019s a player that Voshall thinks has been overlooked in the industry, with all the range going toward players distance or players performance irons.<\/p>\n \u201cIt\u2019s one that I think a lot of players who are the low single-digit handicaps are gonna really like,\u201d he said. \u201cThe feel is there; the performance\u2014 it\u2019s like sneakily forgiving.\u201d<\/p>\n This was always going to be the idea with the Signature Series. Give good ball strikers several options that preserve feel, while allowing them to pick and choose certain features they like, like sole shape, workability and more.<\/p>\n Voshall admitted that this isn\u2019t going to be an iron that flies off the shelf, but it\u2019s also an iron that fits right into the existing Mizuno Pro lineup seamlessly as a combo set. He suggested an S-3 player moving to S-4 in the long irons, or an S-4 player moving to one of the M-Series irons in the long and mid-irons<\/a>.<\/p>\n New shape, same tech<\/p>\n While the S-4 is a more forgiving Mizuno Pro Signature Series iron, it\u2019s hardly just a larger version of the S-3. <\/p>\n Jack Hirsh\/GOLF<\/p>\n Instead, the S-4 is a new shape that features a progressive offset flow and topline throughout the set. This helps the long irons inspire more confidence and keeps the short irons in a more compact profile for precise scoring.<\/p>\n While the S-3 has a straight muscle line along the back of the iron, the S-4 has a new curved muscle that strategically moves mass to the toe and heel, increasing stability and lowering the CG in addition to a wider sole. It also gives the iron a neutral bias.<\/p>\n \u201cThere\u2019s no toe-heel bias to anything; the weighting of that cavity actually has the mass extending up in the toe and the heel,\u201d Voshall said. \u201cSo it\u2019s bringing the CG lower, it\u2019s making the MOI a little bit larger, but all in a small kind of player\u2019s package.\u201d<\/p>\n But, just like the rest of the Mizuno Pro line, the S-4 features the same construction that fans of the brand have come to know and love. The iron is constructed from a single piece of 1025E Pure Select Mild Carbon Steel using Mizuno\u2019s proprietary Grain Flow Forged HD process. The feel is further enhanced by a soft copper underlay and Harmonic Impact Technology. <\/p>\n Jack Hirsh\/GOLF<\/p>\n The S-4 also borrows the Triple Cut sole that\u2019s been a part of more recent Mizuno Pro irons<\/a> such as the M-13 and S-3. The beveled leading edge and increased trailing edge relief help offset the wider sole.<\/p>\n The Mizuno Pro S-4<\/p>\n Jack Hirsh\/GOLF<\/p>\n What is it: While the S-4 is the largest iron in the Mizuno Pro Signature family, it\u2019s still a compact players iron designed for elite ball strikers.<\/p>\n Who it\u2019s for: Players who want a single-piece forged feel, but more forgiveness without the additional speed of a larger iron.<\/p>\n My take: This is the Mizuno iron I\u2019ve been waiting for<\/p>\n For a few years there, Mizuno offered its 223 and 243 cavity-back irons for better players who didn\u2019t want to play blades. But those irons were a bit too jumpy for golfers (like me) who just wanted a little more forgiveness. Mizuno solved this by reprioritizing the new M-13 as a \u201cspeed cavity\u201d and more in the players distance space.<\/p>\n When the S-3 came out, I thought this might have been the option I was looking for, but after playing them for a few months, I realized that the S-3 just didn\u2019t offer the stability I needed. No knock on either of those irons, but they just weren\u2019t for me<\/a>.<\/p>\n With the Pro S-4, Mizuno finally offers the single-piece forged cavity-back that is easy for me to launch and gives me stability for the occasional mishit.<\/p>\n The Pro S-4 is the first iron that truly allows me to experience the Triple Cut sole properly. While the S-4\u2019s sole is wider than the MP-18 MMCs I played a few years ago, it doesn\u2019t play as wide because of the bevels.<\/p>\n At impact, the sole cuts through the turf quickly and makes me feel like I\u2019m picking off a piece of turf the size of a slice of butter.<\/p>\n In the short testing I\u2019ve done, I\u2019ve found it very easy to work the ball up, down, draw, fade, or whatever I want, and as someone who grew up playing Mizuno irons, the look and feel check all the boxes.<\/p>\n For the first time since I\u2019ve been doing this job, it seems like Mizuno finally has the iron that fits my game.<\/p>\n Price, Specs and Availability<\/p>\n Mizuno Pro S-4 Custom Irons<\/a><\/p>\n The Mizuno Pro S-4 has been engineered for accomplished golfers seeking the unmistakable feel of a forged\u00a0iron with greater forgiveness and confidence throughout the set. A redesigned curved muscle concentrates\u00a0mass lower in the head, while progressive offset, a wider sole and deeper center of gravity promote higher\u00a0launch, increased stability and improved forgiveness without compromising the precision expected from\u00a0Mizuno Pro. Forged from a single billet of 1025E Mild Carbon Steel using Mizuno\u2019s patented Grain Flow\u00a0Forged HD process, the S-4 delivers the exceptional feel, feedback and workability synonymous with\u00a0Mizuno\u2019s forged heritage<\/p>\n View Product<\/a><\/p>\n Mizuno\u2019s new Pro S-4 irons are available<\/a> for pre-order starting\u00a0Sept. 3\u00a0and will arrive at retail locations on\u00a0Sept. 17.<\/p>\n The irons cost $215 per club.<\/p>\n Stock lofts are as follows, but can be adjusted through custom:<\/p>\n (3i) 21, 24, 27, 30, (7i) 34, 38, 42, (PW) 46<\/p>\n Want to find the best irons for your game in 2026?\u00a0Find a club-fitting location near you at True Spec Golf<\/a>.<\/p>\n “><\/p>\n","protected":false},"excerpt":{"rendered":"For the first time in more than half a decade, Mizuno has a true better-player cavity-back iron. The…\n","protected":false},"author":2,"featured_media":60648,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3021],"tags":[3123],"class_list":["post-60647","post","type-post","status-publish","format-standard","has-post-thumbnail","category-mizuno","tag-mizuno"],"_links":{"self":[{"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/posts\/60647","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/comments?post=60647"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/posts\/60647\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/media\/60648"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/media?parent=60647"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/categories?post=60647"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/golf\/wp-json\/wp\/v2\/tags?post=60647"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Mizuno](\"https:\/\/www.europesays.com\/golf\/wp-content\/uploads\/2026\/09\/S4Cavity.webp\")
\n The deeper and curved cavity of the Pro S-4.<\/p>\n![\"Mizuno](\"https:\/\/www.europesays.com\/golf\/wp-content\/uploads\/2026\/09\/S4Sole.webp\")
\n The Triple Cut sole of the Mizuno Pro S-4.<\/p>\n![\"The](\"https:\/\/www.europesays.com\/golf\/wp-content\/uploads\/2026\/09\/MizunoProS4AllAngles.webp\")
\n The Mizuno Pro S-4 from all angles.<\/p>\n
\n ![\"Mizuno](\"https:\/\/www.europesays.com\/golf\/wp-content\/uploads\/2026\/09\/pros41.jpg\")
\n <\/a><\/p>\n