Description: Made from made from quality stainless steel to reduce friction and heat. Great for using to cut holes in a variety of materials including steel, brass, wood, plastic, etc. Non-skid tip, no need for center punches. Drill diameters etched in flute for clearly labeled with the depth diameter in steps. Function: deburring, chamfering, cutting or expanding holes. Size Chart: 3-12: 6.25x75mm or 0.25x0.30inch 4-12:6.35x66mm or 0.25x2.60inch 4-20:6.35x75.5mm or 0.25x2.97inch Package Includes: 1 Piece Step Drill Bit or 3 Pieces Step Drill Bit with Pouch(Optional) Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping! Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.