Ridgid 48640 3/4-inch 500B High Speed Bolt Dies 48640 Dies, 500B 3/4 Nc Hs This item is used for Handtools & Tool Organizers ,Other Hand Tools This product manufacture by United States For use with 531, 541 and 500B 1/4"-1" Die Heads RH High Speed 3/4" rod size 10 TPI