#4 SQ Screw Extractor

#4 square flute screw extractor. Removes bolt or screw size 1/2"-9/16". Removes pipe 1/4". Use drill size 5/16", left hand cobalt drill bit suggested.Screw extractors are used when a screw or bolt has broken off while still in the fastening hole. Ideal for thin wall extractions. Will not spread the wall as it extracts.