Kukko screw extractor set, series 49-U, 25 Piece For unscrewing broken screws and bolts Complete with screw extractors, HSS twist drills and drill guide sleeves (drill sleeves) With this kit you can loosen rusted, broken and round screws in 3 steps: 1. Drilling - the damaged bolt / screw is drilled (preferably with the help of the centering sleeve) 2. Hammering - The extractor is hammered in and the extractor nut is attached 3. Turning - With a key, the part is unscrewed from the threaded hole by turning to the left For screws: M5 - M16 (3/16 - 5/8 ") Drill �: 3.2 - 8.7mm