High Quality Material: The center punch tip is made of high speed steel that holds up to strong impact, wear resisting and rust proof to prolong the punch life, high speed steel hardness: HRC58 ~ 60.^ Adjustable Impact Strength: The impact strength is adjustable, and the spring tension can be adjusted for light and heavy strokes, marking, stamping and riveting. More accurate punching.^ Wide Range of Uses:Automatic Center Hole Punch is suitable for a variety of tasks, such as signs on materials, glass window breakers, awl for belt, mark on the wall and so on.Nail spring tool marks your workpiece with a dimple to give you a starting point that prevents screws and drills from wandering; Use this automatic center punch for metal, wood, glass, canvas, plastic, and leather materials.^ Unique Design:Knurled non-slip surface on spring loaded nail punch shaft allows for comfortable work and reduced user fatigue while the precision centered tip increases control for more accurately placed holes.^ How to Use: Use a heavy head to align the positioning point. Press the handle firmly, and then press it toward the punch. After pressing the punch back into the rod for a short time, the powerful spring will force the punch to eject.