Fuel Pressure Take-off Fitting: The fuel pressure take-off fitting is an AN6 male to -6 female with a 1/8" NPT gauge/gage port. The thread size of the 6AN is 9/16-18 UNF. Sealing: The AN thread of the flare is sealed at a 37-degree angle, and the NPT thread is sealed with a 60-degree taper.