The new TaylorMade M3 and M4 irons come from a lineage of designs aimed at making the face more flexible. The company’s history of slots in the sole and then the face, all while further thinning the face, have been key parts of making the face more springy at impact.
But to go the next step, the company is actually adding structures designed to be less flexible.
Known as “Ribcor,” support beams that stretch from the topline to the backbar on both the more compact M3 and higher-launching M4 irons are designed to, as TaylorMade’s vice president of research and development Bret Wahl put it, “quiet the structure.”
“The quest for speed is all about unsupported face area,” Wahl says. “So you’re constantly pushing wall thickness so everything is getting thinned out. That flexibility really drove our team to find ways to focus the deflection of the system in the face.”
What’s essentially happening is the beams make the toe and heel regions rigid while the flexibility brought on by the slots in the face and sole is concentrated in the area of the face that makes contact with the ball.
That structure also controls unwanted vibrations for better sound and feel, and a multi-material badge in the back cavity works further fine tunes the ideal sound. But almost as important as the feel aspect, the Ribcor structure frees up mass to be redistributed to ideal center of gravity locations for the particular performance requirements of the two different irons. One key to that saved weight is how the structure allows the topline rail to get as thin as 1.2 millimeters. Thin ribs strategically placed within the undercut damp vibration. That allows more weight to be redistributed low for higher launch and less spin, as well as around the perimeter for better stability on off-center hits.
The larger M4 is aimed at average golfers and it is designed for higher launch. One key to that higher launch is the structure of the sole slot. The pocket-like design on the M4 features a front wall thickness of just one millimeter to improve face deflection for better low-face impact ball speeds and higher launch. That enables slightly stronger lofts on the M4 for more direct energy transfer and better distance.
The more compact M3, which has a similar shape to last year’s M1, thickens that front wall on the sole slot slightly to better control launch and spin and work more effectively with the M3’s more traditional lofts.
The M3 irons also utilize tungsten in the toe section to improve the off-center hit stability while maintaining a more compact size compared to the M4.
The M3 also incorporates a subtle improvement in the sole design. The leading edge appears straighter from the address position to give better players confidence to work shots, but an increase in the effective bounce makes the more compact iron forgiving through the turf for the steeper swings of even higher handicappers.
The M3 and M4 irons will be available February 16. The M4 irons ($900, with KBS MAX 85 steel shafts; $1,000, with Fujikura ATMOS graphite shafts), while the M3 irons ($1,000 with True Temper XP100 steel or $1,200 with Mitsubishi’s Tensei graphite shafts).