Callaway JAWS MD5 wedge design shows 'a little bit of upsetting the apple cart' when it comes to grooves and spin

The Callaway JAWS MD5 wedges, the company’s most vast wedge offering in its history, reflect a wholesale rethinking of a subject many thought the USGA already had closed the book on: wedge grooves and spin generation. When the new groove rule was instituted back in 2009, it led to a rash of experimentation about grooves and their sizes and volumes and numbers and shapes, but in essence the industry settled on grooves that looked as box-like as possible with steep walls and radiused edges to make them both effective and conforming.

The JAWS MD5, however, is a departure, aimed at providing more spin on the partial shots as you get closer to the green. The higher lofts (56 degrees and up) will feature grooves where the walls aren’t vertical but instead form angles that fall away more from the base of the groove. Under the groove rules, the groove’s edge is regulated by precise formulas and even tighter measurements, but developing the oblique angle on the JAWS MD5 groove’s shape provided new opportunities and the company’s sharpest groove edges ever, said Callaway’s Alan Hocknell, senior vice president of research and development.

“I think you could say this is a little bit of an upsetting of the apple cart,” he said. “Most of the time when people talk about grooves they talk about steep walls as the thing that generates spin, but a lot of the testing we’ve done has suggested that you prize that edge. The edge dominates in generating spin, particularly on short shots where there’s not a lot of deformation on the ball.”

The shape change was as much a shift in theory as it was in manufacturing. Hocknell referred to it as thinking of the manufacturing tolerances not from “the bottom of the groove up, but from the top of the groove down.” He said the new groove design produces not only a sharper edge but a more consistently sharper edge for more consistent spin on short shots.

“When you prioritize it that way, you’re actually able to machine the groove slightly differently, which allows you to hold sharpness and tolerances a lot tighter,” he said.

The new groove improves spin on the partial shots for higher loft wedges, but it’s only part of the story. The rest of the JAWS MD5 lineup of options with 54 degrees of loft or less features the 20-degree wall angle seen in the same lofts of the previous MD4 wedges. (By comparison, the wall angle is 37 degrees on the newly fashioned higher lofts.) The new groove design combines with the company’s “groove-in-groove” surface roughness first introduced with the MD4 wedges. It features three raised ridges between each groove to provide additional friction points—a total of 84 on the face—to grab the ball’s cover at impact.

In addition, the higher lofts have added a new low-bounce version to the company’s “W” or wide sole grind with additional heel relief that Callaway wedge guru Roger Cleveland has been designing for some players on the company’s tour staff over the last two years. That gives the JAWS MD5 lineup four sole grinds. That includes both a high-bounce W-grind to go with the new low-bounce version, as well as an updated C-grind with slightly less bounce and more heel relief; the medium-width S grind with moderate heel relief to keep the leading edge closer to the ground; and the narrow sole, high bounce X-grind for players who hit short shots with moderate to steep attack angles.

The JAWS MD5 lineup features 23 loft and bounce combinations, two more than in the MD4 wedges and the most in company history. The lofts range from 46 to 64 degrees and includes 14 options between 56 and 64 degrees that feature the new aggressive groove edge. The head shapes in the lower lofts are more compact to better match up with typical short iron shapes, while head sizes transition to a

The JAWS MD5 wedges, which feature a 115-gram True Temper Tour Issue steel shaft as well as an 85-gram Project X Catalyst graphite shaft and a lightweight UST Recoil graphite shaft for women’s models, will be in stores Sept. 20 ($170).