High Speed Steel Twist Drills for drilling holes in metal plastic and other creative jewelry designs. Great for Metalsmiths, Goldsmiths, Silversmiths. Use with handpieces and rotary tools. You may also use a jewelers pin vice. Drills store in the convenient plastic storage box. ****See other sizes 50 (1.78mm Diameter) to 80 (0.34mm Diameter) Sold in boxes of 10