Made of the highest grade carbon steel, accurately hardened and tempered preventing splintering and extending life. Powder coated shank protects against rust. Edges accurately tempered to stay sharp. Extra-thick hexagonal shanks minimize roll away. Working ends accurately ground and hardened to HRC 52-58 for maximum service. Striking end hardened to HRC-42 maximum-won't chip or mushroom. Meets Canadian Government specifications CDA39GP-43a. Always use punches and chisels on materials softer than the hardness of the punch itself. Adjustable tension. Always wear safety goggles.