Features:* * Automatically deburrs holes when drilling.* Dual-flute design for faster and smoother cutting.* 4241 high speed steel for long life.* These step drills are ideal for a variety of materials from metal, plastic, fiberglass to wood.* They also help enlarge existing holes.* Dual flute tips have accelerated penetration without chipping.* Applicable to: Electric Drill, Bench Drill, CNC Router Machining Center, Woodworking Machine, CNC Router Advertising, etc.; * Best Suitable Materials: Steel, Stainless Steel, Iron, Brass, Aluminum, WoodSpecifications:* Type: Tapered Step Drill Bit;* Made of: HSS, 4241 High Speed Steel;* Drill Bit Diameter: 4mm - 32mm * Type: 4-12mm, 4-20mm, 4-32mm * Sizes:4-12mm: 4,6,8,10,12mm4-20mm: 4,6,8,10,12,14,16,18,20mm4-32mm: 4,6,8,10,12,14,16,18,20,22,24,26,28,30,32mm Package Contents:1 * Drill Bits