We specifically made two Universal Nuts to mount our tandem combinations and round profile Holey Galahads, one for each of the standard 5/8” (5/8-11) and metric M14 14mm threaded center shaft sizes found on angle grinders worldwide. Only the KAT Universal Nut makes tandem combinations possible. With its 13/16” (21mm) hex head, it also replaces the different manufacturers’ size 2 pin spanner nuts.