New Mizuno MP-59 Irons

With the release of the new Mizuno MP-59 irons, Mizuno uses titanium for a completely different purpose—forgiveness.

While the MP-59 is made from steel, 12 grams of titanium are forged into a pocket behind the face of each club. (It's the slightly darker material in the photo above.) Mizuno says the titanium allows the clubs to maintain the ideal amount of thickness behind the impact area for solid feel while automatically redistributing the weight to the heel, toe and sole of the club.

"The more you push the weight out to the perimeter and the thinner you make it in the middle, there's a trade-off with feel," says David Llewellyn, research and development manager for Mizuno USA. "But by using a lower density material we can maintain thickness here and build in a little bit of forgiveness."

The heads of the MP-59 irons are slightly smaller than last season's MP-58, the first irons released with this feature that Mizuno calls Ti Muscle. Yet Mizuno claims the clubs have a sweet spot that is 5 percent larger. "The MP-58 has a titanium piece that is fairly uniform along the back," says Llewellyn. "On the MP-59 we focused the titanium right in the middle." That should make them perform better on mis-hits than their predecessors, he said.