It is best to use electric hand drill, can not be used the hammer drill mode Use a suitable size screw remover to drill a hole with cutting size and it ’ s easy to extract the screw or bolt using extractor tool 4 pieces screw extractors work with any drill and all the screw size or bolt These extractor tools are used to reverse the damaged screw counterclockwise until it is released Higher hardness and is more than most screw extractors in market, the hardness and the durability are better Striped screw extractor removes even the most stubborn stripped, damaged, embedded, rusted and painted-over screws and bolts, Manufacturer: JLnase3