Alden 3127P Drill-out Broken Bolt Extractor 5/16 in. (8mm) The product is a 5/16" 8MM Power Extractor Purpose of use for Handtools & Tool Organizers, threading-tap-extractors Manufactured in China Bell-shaped drill head allows tool to be pivoted inside drill hole helping to stay on center. No pilot hole required. Self centering drill tip; no walking or wandering. No grinding, center punching required. Works on jagged uneven rough breaks. No grinding, Center punching required. Tempered twice for extra hardness. Results in multiple extractions per tool. Made from M2 HSS. Highest quality steel used and made in the USA.