3b 1st end thread class 12 1st end thread quantity per inch drill 0.5781 dia. hole thru left handside, tap 0.375-18 npt, drill no. 1 hole thru on top of tee, tap 0.3125-24 unf-3b cadmium surface treated un 1st 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