Hydraulic Fittings Identification Guide

Properly identifying hydraulic fittings is essential for preventing leaks and catastrophic system failure. Never mix different thread types or flare angles.

Fitting TypeSealing MethodThread TypeDetails
JIC (SAE J514)37° FlareUNFMost common hydraulic fitting. Uses a 37-degree flare to create a metal-to-metal seal.
ORFS (SAE J1453)O-Ring Face SealUNFHigh pressure sealing using an o-ring seated in a groove on the face of the male fitting.
NPT / NPTF60° TaperedTaperedSeals by thread interference. NPTF (Fuel) provides a better seal without tape than standard NPT.
BSPP (ISO 228)60° ConeParallelCommonly known as G threads. Requires a bonded washer or o-ring to seal.
DIN 235324° ConeMetricEuropean standard using a compression sleeve (ferrule) to bite into the tube.