AUTOMATIC CENTER PUNCH: The automatic center punch provides an automatic, high-impact, spring-loaded strike on the cap; Its brass body has a deep, knurled surface for non-slip control. aluminum can provide convenient storage and transportation. DUAL CUTTING BLADES AND THREE-SIDED SHAFT: Double cutting blades and X-type opening design ensure faster and smoother cutting; 3-sided shank design can prevent the drill chuck from slipping; With the most small pressure, sets can cut through wood, sheet metal, steel and other surfaces. COATING AND TITANIUM: High speed steel makes the step drill bit set more durable, titanium coating can easily cut steel plate, aluminum plate, copper, plastic and wood and many other types of sheet metal. TIME SAVING: Covering assorted pitch sizes makes it possible to drill or enlarge different holes in one drill bit without constantly switching drill bits. The size is laser etched into the metal, so it can be precision drilled and will not wear off not even if used for a long time.