Used on ssn 688 class submarine. 3a internal thread class right-hand external 8 external thread quantity per inch self-locking un external thread series
material: aly steel bar astm a 108, cold drawn, .250 hex.; finish: zincplate per astm B633-85, class fe/zn 12, type ii.; 0.390 in. lg.; thread .138-32unc-2a, min full thd .14