Features:* This drill bit enables it to achieve deburring, chamfering, hole expansion and other functions that other drill bits cannot finish.* Suitable for workpieces with hardness below 25°, such as cast iron plate, aluminum plate, PV plate, insulation plate, etc.* The high-speed steel structure can prolong the service life of the cutting edge even in extreme temperatures. The blue coating increases the drill bit's resistance to heat, corrosion and rust.* Unique step structure, a single drill bit can drill holes in many different sizes.* It is very suitable for cutting holes in various materials, including copper, wood, pvc, aluminum, cast iron, titanium alloy, etc. Fit for pistol drill, hand drill, loading drill, bench drill, etc. Specifications:Product Name: Step Drill BitMaterial: HSS 4241 Color: Blue Shank: 1/4 Hex (6.35mm)Optional Type: Straight Flute, Spiral FluteOptional Size: 4-12mm, 4-20mm, 4-32mm Suitable for: Drilling for Copper, Wood, PVC, Aluminum, Cast Iron, Titanium Alloy, etc. Quantity: 1PcPackage Contents:1 x Step DrillNote:1. Transition: 1cm=10mm=0.39 inch.2. The actual colors of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.3. Please allow slight manual measurement deviation for the data.