The PTI HSS Tin-Coated Step Drill 4 - 12mm is designed for versatile drilling in a range of sizes with a single bit. Perfect for working with thin materials such as sheet metal up to 6.5mm, this step drill offers a progressive and precise cutting solution. Size Range : 4.0 - 12mm, with increments: 4.0, 6.0, 8.0, 10.0, 12.0mm Material : High-speed steel (HSS), Tin coated Shank Type : 1/4” Hex Drive Features : Self-starting with multiple hole sizes Ideal for drilling thin, rigid materials like sheet metal Provides a chamfered edge and smooth finish Brand : PTI