1、TITANIUM HIGH SPEED STEEL: Drill bits is made of titanium high speed steel, which have higher hardness and wear resistance 2、OPENING DESIGN: This drill adopts 118° X shaped opening design, which can effectively prevent the drill from slipping 3、DOUBLE STRAIGHT FLUTES: This drill bit with double straight flutes, which for fast drilling and unhindered chip evacuation 4、MEET NEEDS: A variety of stepped drill step sizes, easy to use, dual purpose sawing, drilling, drilling and milling, fast and efficient 5、WIDE APPLICATIONS: The drill set can be used for grooving, reaming and punching of thin wood, metal and plastic plates, etc. Item Type: Titanium HSS Drill Set Material: Titanium Plated High Speed Steel Shank Type: Round Shank Blade Diameter(Approx.) Overall Length(Approx.) Shank Diameter(Approx.) 4mm-12mm Step Drill Bit 4mm / 0.16in,6mm / 0.24in,8mm / 0.31in,10mm / 0.40in,12mm / 0.47in 65mm / 2.56in 6mm / 0.24in 4mm-20mm Step Drill Bit 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 73mm / 2.87in 8mm / 0.31in 4mm-32mm Step Drill Bit 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 101mm / 4.00in 10mm / 0.40in 3mm Saw Drill 3mm / 0.12in 60mm / 2.36in 3mm / 0.12in 6mm Saw Drill 6mm / 0.24in 85mm / 3.35in 6mm / 0.24in 8mm Saw Drill 8mm / 0.31in 93mm / 3.66in 8mm / 0.31in 3 x Straight Grooved Step Drill Bit 3 x Titanium HSS Drill Bit