3a all ends thread class 18 2nd end thread quantity per inch third end bulkhead, unf, 0.750 in. td size, 3a class anodize surface treated unf 1st end thread series
Used on jzn mars class afs. 6 bolt hole quantity 3 thd holes on bolt circle 3/8-16-unc, 120 deg apart; 3 unthd on same bolt circle round, one bolt hole circle
3a 2nd end thread class 12 2nd end thread quantity per inch precious metal, gold, weight, 0.0025 pound per coupling, gold brazing ring located on first end passivate surface treated rigid, short center wrenching facility unj 2nd end thread series
