Made of high-quality high-speed steel that is hard and sharp enough to drill through wood, plastic, steel and sheet metal Optimized for impact driver usage, automatically deburr holes as you drill Ready to use in a thin iron plate, aluminum, insulation panels, PVC panels 4mm thickness within the timber. 3 standard SAE step drill bits can drill 28 different sizes of holes on different thickness of materials. Specification: Measurement System: inch Item Weight: 3.8 ounces Model: DWB14 Color : Metallic Golden Material : High speed steel Shank :1/4" Hexagonal (6.35 mm) Surface treatment: Titanium coated (10nm) Lenght, Dia steps: Six step bit: 3/16", 1/4", 5/16", 3/8", 7/16", 1/2" drilling diameter, up to 3/8" depth of each step Nine step bit: 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4" drilling diameter, up to 3/16" depth of each step Thirteen step bit: 1/8", 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2" drilling diameter, up to 1/8" depth of each step Features : Titanium coated surface can reduce friction and overheat when drilling through the material for a longer lifetime. Two-flute design provides faster, smoother and accurate cutting 1/4" hex shank (6.35mm)can be easily fit into power driver, drill and press drill. Used to cut holes in a variety of material like thin steel iron, wood, aluminum alloy, insulation boards, PVC sheet, Concrete. ??te: Star drilling at low speed. Do not push too much. Let the drill bit to cut by itself. The harder the material it is working with, the lower speed shall be applied. Inject coolant oil while working, it will dramatically increase the drilling efficiency and extend the drill bit lifetime Drill bits are good for wood, plastic, steel and sheet metal drilling. Stainless steel is not recommended. Package Included : 1pc x 3/16"- 1/2" Step Drill Bit 1pc x 1/4" - 3/4" Step Drill Bit 1pc x 1/8" - 1/2"Step Drill Bit 01011706