JIC vs ORFS vs NPT: Hydraulic Fitting Types Explained
By AIM Rentals ·
Ordering the wrong hydraulic fitting is the fastest way to lose a day on a repair. The three connection types you'll meet most on heavy equipment in North America are JIC, ORFS, and NPT — and they are not interchangeable. Here's how to tell them apart.
JIC (37° flare)
JIC fittings seal metal-to-metal on a 37-degree flared cone. The male has a straight thread and a flared seat; the female swivel nut pulls the two cones together. They're the most common connection on mobile equipment hoses, re-usable, and tolerant of repeated assembly. If your fitting has a visible cone-shaped seat and no O-ring, it's most likely JIC.
ORFS (O-ring face seal)
ORFS fittings seal with an O-ring captured in a groove on the flat face of the male fitting. They handle higher pressures with better leak resistance than JIC, which is why newer excavators and loaders — including many Cat, Komatsu, and Volvo machines — use them extensively. Flat face plus O-ring groove = ORFS.
NPT (tapered pipe thread)
NPT threads are tapered — the seal happens as the threads wedge together, usually with sealant. Common on ports, gauges, and low-pressure plumbing rather than hose ends. If the thread diameter visibly shrinks toward the end of the fitting, it's a tapered pipe thread.
How to measure before you order
- Use a caliper to measure the thread outside diameter on males (inside diameter on females).
- Count threads per inch with a pitch gauge — or match against a known fitting.
- Check the seat: 37° cone = JIC, flat face with O-ring = ORFS, tapered thread = NPT.
- Note both ends — hoses frequently have different connections at each end.
Metric and specialty connections
European and Asian machines add metric DKOL/DKOS (24° cone with O-ring), BSPP, JIS, and SAE flange (Code 61/62) connections. We stock adapters between most families — see hydraulic adapters and hoses and fittings, or use our hose builder to spec a complete assembly.
Not sure what you have? Email a photo and measurements to sales@rentwithaim.ca — we'll identify it the same business day. Shipping included on Canadian orders.