SCREW EXTRACTOR SET,HRC45-48, QUANTITY: SIX PIECE, MATERIAL: CARBON STEEL, WITH HARDNESS: 45 TO 48 HRC, FOR EXTRACTING BROKEN SCREWS AND STUDS, FOR MID TENSILE STRENGTH SCREWS AND STUDS, 1) FOR SCREW 1/8 TO 1/4 INCH OR M3 TO M6, 2) FOR SCREW 1/4 TO 5/16 INCH OR M6 TO M8, 3) FOR SCREW 5/16 TO 7/16 INCH OR M8 TO M11, 4) FOR SCREW 7/16 TO 9/16 INCH OR M11 TO M14, 5) FOR SCREW 9/16 TO 3/4 IN CH OR M14 TO M18, 6) FOR SCREW 3/4 TO 1 INCH OR M18 TO M25.