Radial Face / HSM Insert

The Bobby Grace Radial Face Putter with HSM2 Insert is built around two ideas working together: a face shape and an insert material meant to change how the putter behaves at contact. According to bobbygraceputters.com, the face itself is a unique radial face cut with polymer grooves, and it's paired with an HSM2 multi-rebound core insert, described as a Hole Seeking Material, set into that face.

The site's account of the putter's development describes 18 months of trial and error using CAD/CAM/CNC work alongside velvet roll board testing with high-speed cameras, which points to a design process aimed at refining feel and roll consistency rather than simply arriving at a shape and calling it finished. The stated result of that radial face and grooved geometry is a sweet spot that bobbygraceputters.com describes as growing from 1/2 inch to 1 1/2 inch, a claim about forgiveness that comes from the maker's own account rather than independent testing.

Within the Radial Face and HSM Insert line, this release represents the version built specifically around the HSM2 core, tying the radial face concept to that particular insert generation. The record here draws entirely from the maker's own published description, so the design story, the face and insert pairing, and the sweet spot figures should all be read as Bobby Grace's account of the putter rather than a third party's independent measurement of it.