WHAT IT DOES: Ping engineers said they want to make the i525 “as ballistic as possible but with the proper balance of blade length, offset and top-rail thickness.” To achieve this, Ping uses a forged, variable-thickness, maraging-steel face in a hollow-construction iron. The strength of the maraging steel allows the face to flex, but that rebound is enhanced through the use of an internal sole undercut that allows stress to move deeper into the sole. This reduces stress on the face to allow for more uniform bending in the center of the face. That increases ball speed but makes it more predictable. 

WHY WE LIKE IT: Although ball-speed gains and changes in appearance are apparent, several design heroes won’t be as easily detected. Chief among them is a change in how the company applies hot melt—a polymer used inside the clubhead—to enhance sound and weighting properties. Previously the amount of hot melt wasn’t consistent from club to club. Here four grams are placed strategically in every head. This allows for a cohesive sound and feel throughout the set and gets rid of higher-pitched frequencies for a quieter sound that makes the impact experience better. Read more>>