Check the listing for details. TP PD343 - Aftermarket Flat Face Diagnostic Nipple 1/4 MPT. Condition: New. Listed at 17.43 USD. Aftermarket Flat Face Diagnostic Nipple 1/4 MPT (Parker PD343 Aeroquip FD90-1034-04-04) NPTF (PIPE) THREAD CHART - THREAD SIZE MEASUREMENT TAKEN FROM OUTSIDE DIAMETER OF MALE THREADSDryseal American Standard Taper Pipe Thread (NPTF) which is usually reffered to as just pipe thread or tapered pipe thread seals in one of two ways. The first method is interferance between the threads on the male and female connectors - a thread sealant is typically used in this application. The second method is 30° inverted flare on the nose of the fitting. This is typically used when connecting a male connector to a female swivel connector. In this application thread sealant is not used. Dash Size Nominal Size Thread Size - 21/8".405" - 27- 41/4".540" - 18- 63/8".675" - 18- 81/2".840" - 14- 123/4"1.050" - 14- 161"1.315" - 11.5- 201-1/4"1.660" - 11.5- 241-1/2"1.900" - 11.5- 322"2.375" - 11.5