With the Rennsteig screw extractor set 9R 471 901 3, you can remove damaged, seized, or broken screws and studs quickly and with full control. The two cutting edges bite firmly into the pre-drilled hole, allowing you to back out both right-hand and left-hand threads from M5 to M20 without damaging the internal workpiece thread. This eliminates the need for tedious drilling out and re-tapping during maintenance and overhaul tasks. Made from hardened chrome-vanadium steel, the five extractors in sizes 1 to 5 provide outstanding wear resistance and stay neatly organized in the sturdy metal case, ready for any repair job.