Features 1、Automatically deburrs holes as you drill. 2、Two-flute design gives you faster, smoother cutting. 3、Titanium nitride coating for cooler running. 4、Quick-change 1/4/" hex shank. 5、Manufactured from high speed steel for increased durability and cutting power. 6、Used for variety of materials from metal, plastic, fiberglass to wood. 7、They also help to enlarge existing holes. Specification The 3pcs step cone drill bits are suitable for cutting hole in a variety of materials including steel, brass, wood, plastic, etc. Features: Automatically deburrs holes as you drill. Two-flute design gives you faster, smoother cutting. Titanium nitride coating for cooler running. Quick-change 1/4" hex shank. Manufactured from high speed steel for increased durability and cutting power. Used for variety of materials from metal, plastic, fiberglass to wood. They also help to enlarge existing holes. Specifications: Material: High-speed steel Color: Gold Size: 3-12mm/4-20mm/4-12mm Package Weight: 100g / 3.53ounces Package Size: 120 * 100 * 20mm / 4.72 * 3.94 * 0.79in Packing List: 3 * Step Cone Drill Bits 1 * Pouch Package List 3 * Step Cone Drill Bits 1 * Pouch