The IRWIN Max Strike 15 oz. High Velocity One Piece Steel Hammer is carefully engineered to be more efficient. It’s built from the grip up with tradespeople in mind. Lightweight, yet designed to strike like a heavier hammer. The 15 oz. is designed to have same striking effect as a 20 oz. hammer. Faster swing, more productive, yet less arm fatigue. Its ergonomic grip is built to reduce vibration and transfer less shock to the body.