The HEX triple dimple jig integrates 3 jigs into one tool. Its machined from 1045 carbon steel hex stock with 0.420", 0.460" and 0.500" center to center on holes and a 0.765" bore. 1045 carbon steel hex stock Heat treated - 60 rockwell C Black zinc coating Includes pointed and soft point set screws 11/64" drilling holes Mfg: Black Rifle Disease Engineerin