2a 1st end thread class 12 all ends thread quantity per inch second end bulkhead, un, 1.625 in. thd size, 2a class cadmium surface treated un all ends thread series
3a 2nd end thread class 12 1st end thread quantity per inch second end bulkhead, um, 1.062 in. thd sizee, 3a class anodize inside surface treated un 1st end thread series
2b 2nd end thread class 12 1st end thread quantity per inch machined groove in flared ends to accommodate seal rings per KC103 passivate outside surface treated un 3rd end thread series
2b 3rd end thread class 12 1st end thread quantity per inch machined groove in flared ends to accommodate seal rings per KC103 passivate outside surface treated un 3rd end thread series
3a 2nd end thread class 12 1st end thread quantity per inch machined groove in flared ends to accommodate seal rings per KC103 passivate inside surface treated un 1st end thread series