Apexx 10101-01005 Adapter 5/8-Inch 11-Male Thread to 3/8-Inch Straight Shank for Electric Hand Drills 5/8"-11 male thread to 3/8" straight shank Converts electric hand drill to 5/8"-11 thread For use of Apexx and other core drill bits on electric hand drills This adapter is very strong and durable thanks to our design and the tough steel