3a 1st END3a 2nd end thread class 16 1st END16 2nd end thread quantity per inch flared tube to 90 deg elbow to bulkhead universal unjf 1st endunjf 2nd end thread series
3a 1st end bulkhead thread class ivd coating, ion vapor deposited, 99 per cent pure aluminum coating, mil-c-83488 aluminum surface treated unjf all ends thread series