▲ 50 Size in 5 - The bits set includes five standard step drill bits that can replace 50 individual drill bits, you can process 50 different kinds of diameter holes with the five pieces | ▲ Hss & Titanium Coating - High speed steel makes it last longer than others, titanium coating ensures easily cut through steel sheets，aluminum sheets，copper & plastic & wood board and many other types of sheet metal with ease, and it can automatically deburr holes while drilling to keep the drill bit clean | ▲Automatic Center Punch & Protective Aluminum Case - the center punch delivers an automatic, high-impact, spring-loaded strike through adjusting the cap; its brass body has a deeply knurled surface for nonslip control; and the carbide tipped bit makes the center punch 10 times stronger than normal one;protective aluminum case makes the drills not easy to dull | ▲Double Cutting Blades & Three-Sided Shank - Double cutting blades and X-type openings design ensures a faster and smoother cutting; and 3-sided shank design prevents slip in drill chuck; Provided with small pressure and the sets can cut through the wood, sheet metal, steel and other surfaces | ▲What You Get - TACKLIFE Step Drill,Automatic Center Punch, Aluminum Case, User's Manual