This high-quality, round hex/spline, 12 In. tamper plate shank works with the HS1828 tamper plate and the HS1969 carbide bushing tool. All Bosch chisels are manufactured with a proprietary heat-treat process. Bosch offers a full assortment of round hex/spline hammer steel points and chisels. Bosch brings constant innovation to concrete and masonry drilling with increased efficiency and higher durability.