This versatile double-ended bit removes damaged screws, machine screws and broken bolts from wood, metal and plastic. It can remove screw sizes from Nos. 6 - 14 and broken bolts from size M4 - M8. Removes cleanly from wood, metal or plastic. Hardened tool steel. Removes screws made of any alloy including soft brass. Removes free spinning screws. Winslow tip for self centring. Double-ended (burnisher & tapered thread). Hex shoulder to aid removal of jammed screw or bolt.Patent Nos. WO2004002687 & US6,761,089Set of two.