A ball-peen hammer (often referred to in industrial settings as a safety ball hammer) is a handheld striking tool engineered primarily for metalworking, riveting, and striking chisels or punches. Its technical architecture consists of a heavy, hardened forged-alloy steel head securely mounted to an ergonomic handle made of shock-absorbing hickory wood, fiberglass, or rubberized composite. The head features two distinct functional faces: a flat, polished circular face called the “poll,” which is designed for striking structural tools or driving fasteners, and a hemispherical face called the “peen,” which is used to shape metal, expand the shafts of rivets, and relieve structural stress in welds through peening.

Operation relies on manual kinetic energy transfer and controlled striking velocity. The operator grips the lower third of the handle to maximize leverage and swings the hammer in a smooth, fluid arc, allowing the weight of the steel head to generate the necessary impact force rather than relying solely on muscle power. When striking a punch or chisel, the flat poll must make square, perpendicular contact with the target surface to prevent glancing blows that could cause structural damage or flying debris. For metal fabrication or riveting, the user flips the tool to utilize the rounded peen, which strikes the metal to stretch it or expand a rivet head uniformly.