JIC vs ORB Fittings: How They Differ
JIC and ORB fittings share the same threads in every dash size but seal in completely different ways. Here is how to tell them apart and connect them correctly.
Last updated October 30, 2026. Reference values; verify against manufacturer specifications.
JIC and ORB (O-ring boss) fittings are often found on the same machine, sometimes on the same adapter. They use the same thread sizes for each dash number, which is exactly why they get mixed up. The way they seal is completely different, and a fitting of one type will not seal in a port or seat of the other.
The short answer
- JIC 37° (SAE J514) seals metal-to-metal on a 37° flare. It is used to connect hose and tube ends to each other or to adapters.
- ORB (SAE J1926 port, also listed as ISO 11926) seals with a rubber O-ring that is squeezed into a chamfer at the mouth of a straight-thread port. It is used where a fitting screws into a component such as a pump, valve, cylinder or manifold.
- For the same dash size, both use the same UN/UNF thread. A -6 JIC and a -6 ORB are both 9/16-18.
How a JIC 37° connection seals
A JIC joint is made of a male end with a 37° cone-shaped nose and a female swivel nut with a matching 37° seat (or a flared tube held by a nut and sleeve). Tightening the nut presses the two cone surfaces together. The seal is the metal contact on the cone; the threads only provide the clamping force.
Because the seal is on the cone, a JIC joint can usually be taken apart and remade, provided the seats are not scratched, cracked or flattened from overtightening. It is also the reason JIC fittings are assembled dry, without thread tape or sealant.
How an ORB connection seals
An ORB port is a straight (parallel) thread machined into a component, with a flat spot face and a small chamfer at the top of the thread. The male ORB fitting carries an O-ring just below its hex or locknut. When the fitting is tightened, the O-ring is compressed into the chamfer and against the spot face, and that compressed O-ring makes the seal.
The O-rings are a dedicated series (often listed as AS568 900-series), and the O-ring number follows the dash size: a -4 ORB uses a 904, a -6 uses a 906, a -8 uses a 908, and a -16 uses a 916. Replacing the O-ring with the correct size and compound is part of reusing an ORB fitting.
ORB fittings come in two styles:
- Non-adjustable (straight) ORB: the O-ring sits in a groove under the hex. Used for straight adapters and plugs.
- Adjustable ORB: used on elbows and tees. A locknut and backup washer sit above the O-ring, so the fitting can be turned to point the right way before the locknut is tightened.
JIC vs ORB at a glance
| Feature | JIC 37° flare | ORB (O-ring boss) |
|---|---|---|
| Standard | SAE J514, ISO 8434-2 | SAE J1926 (port), ISO 11926 |
| Seal type | Metal-to-metal on a 37° cone | Elastomer O-ring in a port chamfer |
| Thread type | Straight UN/UNF | Straight UN/UNF |
| Thread for a given dash size | Same as ORB | Same as JIC |
| Where it is used | Hose ends, tube nuts, adapter ends | Ports in pumps, valves, cylinders, manifolds |
| What you see on the male end | Cone-shaped nose in front of the threads | Flat end; O-ring or O-ring groove near the hex |
| What you see on the female side | Swivel nut with a 37° seat inside | Threaded port with a spot face and chamfer, no cone |
| Reuse | Reusable if the seats are undamaged | Reusable with a new O-ring |
| Thread sealant | Not used | Not used (O-ring seals) |
Shared thread sizes
Both systems use the same straight threads for each dash size, for example:
- -4: 7/16-20 UNF
- -6: 9/16-18 UNF
- -8: 3/4-16 UNF
- -10: 7/8-14 UNF
- -12: 1-1/16-12 UN
- -16: 1-5/16-12 UN
The full list of JIC threads is in the JIC fitting size chart. Matching threads are convenient for adapters (one dash size, one thread) but they also mean that a wrong fitting will thread in and feel normal until the system is pressurized.
How to tell a JIC fitting from an ORB fitting
- Look at the end of the male fitting. A JIC male has a smooth cone (the 37° nose) ahead of the threads. An ORB male ends flat, with no cone.
- Look near the hex. An ORB male has an O-ring or an O-ring groove just below the hex, or a locknut and washer on adjustable styles. A JIC male has threads running up to a plain shoulder.
- Look inside the female side. A JIC female swivel nut has a 37° seat inside. An ORB port has no internal cone: just threads, with a flat spot face and a small chamfer at the top.
- Check where it lives. If it is a hole machined into a pump, valve or cylinder body, it is a port (ORB is common on SAE inch equipment). If it is a nut on the end of a hose or tube, it is a connection like JIC.
- Confirm with a seat gauge if a cone is present. A 37° reading means JIC; see how to measure JIC fittings.
Can a JIC fitting go into an ORB port?
A male JIC end will usually thread into an ORB port of the same dash size because the threads match. It will not seal correctly. There is no O-ring, and the JIC cone has nothing to seal against in a port, so the connection relies on thread contact alone. Under hydraulic pressure that is likely to leak and may fail.
The reverse also does not work: an ORB male has no 37° cone, so a JIC female swivel tightened onto it has no seat to seal on.
The usual solution is an adapter with a male ORB on one end (to go into the port) and a male JIC on the other (to receive the hose or tube nut). These are common straight, 45° and 90° parts and are often described as "male JIC to male ORB" adapters.
Why both systems are often used together
Many machines combine them on purpose. The ORB side gives a reliable, reusable seal into a component port, with a soft O-ring that tolerates the small movements and vibration of a pump or valve body. The JIC side gives a metal-to-metal connection for hoses and tubes that can be disconnected and reconnected without replacing seals. Using a JIC-to-ORB adapter keeps each seal type doing the job it was designed for.
Some newer designs use ORFS (O-ring face seal, SAE J1453) for the hose connection instead of JIC. ORFS has a flat face with an O-ring rather than a cone, and its threads are different from JIC and ORB. See JIC vs ORFS.
Practical tips
- Replace ORB O-rings whenever the fitting is removed, and lubricate them lightly with system fluid before assembly.
- On adjustable ORB fittings, back the locknut and washer up first, thread the fitting in until the washer touches the spot face, orient it, then hold the body and tighten the locknut.
- Inspect JIC cones and seats for scratches, cracks or flattening before reuse.
- Do not use thread tape or sealant on either type. Neither seals on the threads.
- Follow the fitting manufacturer's assembly torque or FFWR values. See common JIC fitting mistakes for the basics of the flats-from-wrench-resistance method.
References
Seal descriptions and standards are based on published manufacturer and distributor guides, including the Eaton Thread Identification Guide, Ryco's ORB and JIC technical data, and the Maxbar SAE J514 end-fitting chart. Always verify part details against the fitting manufacturer's specifications.
Frequently asked questions
Do JIC and ORB use the same threads?
Yes. For a given dash size, JIC and ORB use the same straight UN/UNF thread, for example 9/16-18 for -6 and 3/4-16 for -8.
Will a JIC fitting seal in an ORB port?
No. It may thread in, but the ORB port seals with an O-ring that a JIC fitting does not have. Use a male JIC to male ORB adapter.
What O-ring does a -6 ORB fitting use?
ORB fittings use a 900-series O-ring numbered to the dash size, so a -6 ORB typically uses a 906 O-ring. Confirm the material with the fitting manufacturer.
Is ORB the same as ORFS?
No. ORB seals with an O-ring in a threaded port. ORFS (O-ring face seal) seals with an O-ring on a flat face between two fittings and uses different threads.
How can I tell an ORB port from a JIC female?
An ORB port is machined into a component and has threads, a spot face and a small chamfer, but no internal cone. A JIC female is a swivel nut with a 37° seat inside.