Product SpecificationsType: Step Drill BitMaterial: High Speed Steel 4241Size: 3/16" to 7/8"3/16(4.76mm), 1/4(6.35mm), 5/16(7.94mm), 3/8(9.53mm), 7/16(11.11mm), 1/2(12.7mm), 9/16(14.29mm), 5/8(15.88mm), 11/16(17.46mm), 3/4(19.05mm), 13/16(20.64mm), 7/8(22.22mm）Surface treatment: Titanium plating (Golden)Suitable hardness: Hardness below 25°Workpiece thickness: Less than 5 mmFeatures1, Deburring, chamfering, round hole reaming, it can complete the function that the twist drill can not complete2, Two-Flute Design for smoother cutting and faster removal of chips3, Tri-flatted side cutouts fits into power tools chuck securely and offer stronger grip for standard drill chuck4, Perfect for drill holes in steel, copper, plastic, aluminum, and other thin materials (Thickness is below 5 mm)5, Use tools: hand drill, bench drillPackaging Includes1pc * 3/16" to 7/8" Step Drill Bit【Please NOTE】Please use water to cool when working, which can effectively extend the service life of the drill bit. The recommended drilling speed is 250-400 rpm!