ClubTest First Look: Srixon’s hollow ZX4 irons combine human and artificial intelligence

srixon zx4 irons

Srixon's ZX4 is fully hollow iron created to bring forgiveness to the Srixon lineup.

Jonathan Wall

Club designers continue to pull the strings during the club creation process, but over the last few years, computers have started to shoulder more of the design load. Srixon’s ZX4 iron is the latest example.

Combining human and artificial intelligence, Srixon’s design team created a mid-sized, hollow cavity iron set that blends the feeling of a forged iron with the forgiveness of a game-improvement model. A forged HT1770 maraging steel face is the engine behind ZX4’s impressive speed, but instead of simply adding the material as-is, designers allowed a computer to refine the design through thousands of simulations.

The end result is a “mainframe” design that’s milled into the backside of each face. The intricate design consists of grooves, channels and cavities in a variable thickness pattern that expands the sweet spot and amplifies ball speed across the entire face structure. In addition to the face design, each iron features a hollow 431 steel cavity with high-density tungsten slugs situated in the toe section — long and mid irons — to increase launch.

srixon zx4

Spin, launch and distance characteristics are optimized through a progressive groove design. The 4- through 7-iron grooves are slightly wider while the 8-iron through pitching wedge offers a tighter, deeper groove that’s geared to cut through the grass and maintain spin consistency on approach shots.

Turf interaction has been refined with the help of Srixon’s unique Tour V.T. Sole. Heel and toe notches located along the sole enhance workability without compromising how the club enters and exits the ground.

Srixon’s ZX4 irons (4-AW) are available March 5 and retail for $1,300 (8-piece steel)/$1,400 (8-piece graphite).

Want to overhaul your own bag for 2021? Visit the expert fitters at our sister company, True Spec Golf. For more on the latest gear news, check out our latest Fully Equipped podcast below.

Check out the Pro Shop for all your equipment needs

JWall

Jonathan Wall

Golf.com Editor

Jonathan Wall is GOLF Magazine and GOLF.com’s Managing Editor for Equipment. Prior to joining the staff at the end of 2018, he spent 6 years covering equipment for the PGA Tour. He can be reached at jonathan.wall@golf.com.