Features Titanium Plated High Speed Steel: Drill bit is made of titanium plated high speed steel have higher hardness and wear resistance 118° X Type Opening Design: Drill bit adopts 118° X type opening design, which can effectively prevent the bit from slipping Easy to Use: Step drill is easy to use, sawing and drilling, drilling and milling are dual purpose, fast and efficient Double Spiral Flute: This double spiral flute step drill is not only convenient for chip removal, but also protects the cutting edge Wide Applications Range: Widely used for slotting, reaming and punching of thin wood, metal, and plastic plates, etc. Specification: Item Type: Spiral Grooved Step Drill Bit Material: Titanium Plated High Speed Steel Shank Type: Hex Shank Step Drill, Round Shank Saw Drill 4mm-12mm Step Drill Bit: Blade Diameter: Approx. 4mm / 0.16in, 6mm / 0.24in, 8mm / 0.31in, 10mm / 0.40in, 12mm / 0.47in Total Length: Approx. 65mm / 2.56in Shank Diameter: Approx. 6.35mm / 1/4in 4mm-20mm Step Drill Bit: Blade Diameter: Approx. 4mm / 0.16in, 6mm / 0.24in, 8mm / 0.31in, 10mm / 0.40in, 12mm / 0.47in, 14mm / 0.55in, 16mm / 0.63in, 18mm / 0.71in, 20mm / 0.80in Total Length: Approx. 73mm / 2.87in Shank Diameter: Approx. 6.35mm / 1/4in 4mm-32mm Step Drill Bit: Blade Diameter: Approx. 4mm / 0.16in, 6mm / 0.24in, 8mm / 0.31in, 10mm / 0.40in, 12mm / 0.47in, 14mm / 0.55in, 16mm / 0.63in, 18mm / 0.71in, 20mm / 0.80in, 22mm / 0.87in, 24mm / 0.94in, 26mm / 1.02in, 28mm / 1.10in, 30mm / 1.18in, 32mm / 1.26in Total Length: Approx. 101mm / 3.98in Shank Diameter: Approx. 6.35mm / 1/4in 3mm Saw Drill: Blade Diameter: Approx. 3mm / 0.12in Total Length: Approx. 60mm / 2.36in Shank Diameter: Approx. 3mm / 0.12in 6mm Saw Drill: Blade Diameter: Approx. 6mm / 0.24in Total Length: Approx. 85mm / 3.35in Shank Diameter: Approx. 6mm / 0.24in 8mm Saw Drill: Blade Diameter: Approx. 8mm / 0.31in Total Length: Approx. 93mm / 3.66in Shank Diameter: Approx. 8mm / 0.31in (Parameters are manually measured, there is a certain error) Package List: 1 x 4-12mm Spiral Grooved Step Drill Bit 1 x 4-20mm Spiral Grooved Step Drill Bit 1 x 4-32mm Spiral Grooved Step Drill Bit 1 x 3mm Saw Drill Bit 1 x 6mm Saw Drill Bit 1 x 8mm Saw Drill Bit 1 x Plastic Box Package List 1 x 4-12mm Spiral Grooved Step Drill Bit 1 x 4-20mm Spiral Grooved Step Drill Bit 1 x 4-32mm Spiral Grooved Step Drill Bit 1 x 3mm Saw Drill Bit 1 x 6mm Saw Drill Bit 1 x 8mm Saw Drill Bit 1 x Plastic Box