High Quality Material: Step Cone Drill Bits are made of high speed steel and titanium nitride is coated to reduce frictional heat and cool. Strong and durable. Two-Flute, Split-Point Design: The two-flute, split-point design prevents slipping, clears chips quickly and deburrs holes, with reduced pressure, faster, smoother drilling and cutting. 3 Pitch Sizes: Different Sizes Can Meet Different Needs, Design For Precision Drilling Different Size Holes From 4mm To 32mm In Diameter, Covering Various Pitch Sizes Help To Drill Or Enlarge Different Holes In One Bit, Optimal Speed And precision. Suitable for: Widely applicable for cutting or enlarging holes in materials like thin steel, thin metals (thickness5mm), wood, thin iron, plastic, aluminum, PVC, fiberglass and etc. Material: HSS Steel + Coated TitaniumType: Drill pressQuantity: 3PCSGold colorUsage: Aplly in gun drilling, drill benchCut:Jaws 5 steps: 4-12mm (4mm, 6mm, 8mm, 10mm, 12mm). 9 Jaws: 4-20mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 14mm, 16mm, 18mm, 20mm). 15 jaws pitch: 4-32mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 2mm). Note:1. Wear safety glasses before drilling. 2. Please cool with water when working because of the high temperature, to extend the service life of the wick and prevent clogging. 3. The speed is advised to be 250-400RPM / Min.