1. THE METHOD COMPRISING FORMING ON AN ELEMENT A THREAD ADAPTED TO INTERFIT WITH A COACTING THREADED MEMBER AND HAVING A MAJOR DIAMETER PORTION AND A MINOR DIAMETER PORTION AND A THREAD FACE RADIALLY THEREBETWEEN, APPLYING RADIAL FORCE TO A LOCALIZED AREA OF SAID THREAD HAVING A LIMITED AXIAL EXTENT WHICH IS SHORT AS COMPARED WITH THE FUELL AXIAL LENGTH OF THE THREAD, THEREBY RADIALLY OFFSETTING SAID MAJOR AND MINOR DIAMETER PORTIONS OF SAID THREAD AND SAID INTERMEDIATE THREAD FACE AT SAID LOCALIZED AREA RELATIVE TO CORRESPONDING PORTIONS OF THE THREAD AT OTHER LOCATIONS AND IN A DIRECTION TO INTERFIT WITH SAID COACTING MEMBER MORE TIGHTLY AND THEREBY ATTAIN A SELF LOCKING ACTION, AND SUBSEQUENTLY REMOVING MATERIAL AT SAID LOCALLY OFFSET MAJOR AND MINOR DIAMETER PORTIONS TO RELIEVE THE TIGHTNESS OF THE THREAD INTERFIT AT THOSE LOCATIONS, WHILE LEAVING SAID INTERMEDIATE THREAD FACE LESS RELIEVED TO INTERFIT MORE TIGHTLY THAN SAID MAJOR AND MINOR DIAMETER PORTIONS WITH SAID COACTING MEMBER.