ORFS Fitting Thread Sizes: O-Ring Face Seal SAE J1453 Data
ORFS (SAE J1453) Thread Sizes
| Dash Size | Tube OD | Thread |
|---|---|---|
| -4 | 1/4" | 9/16-18 UNF |
| -6 | 3/8" | 11/16-16 UN |
| -8 | 1/2" | 13/16-16 UN |
| -10 | 5/8" | 1-14 UNS |
| -12 | 3/4" | 1-3/16-12 UN |
| -16 | 1" | 1-7/16-12 UN |
| -20 | 1-1/4" | 1-11/16-12 UN |
| -24 | 1-1/2" | 2-12 UN |
ORFS is the leak-proof fitting. An O-ring sits in a groove on the flat face of the fitting and seals against a flat machined surface. No thread sealant, no flare quality to worry about. When you need zero leaks in a high-pressure, high-vibration environment, ORFS is the answer. The downside is cost and you cannot field-fabricate the tube end without proper tooling.
When to Use ORFS (SAE J1453)
High-vibration mobile equipment, factory automation, and any application where zero leaks are required.
ORFS is the upgrade from JIC when vibration causes JIC flares to loosen over time.
Many OEMs are switching to ORFS for new machine designs.
ORFS (SAE J1453) Limitations
More expensive than JIC. Requires proper O-ring replacement if the seal is damaged.
Cannot field-fabricate tube ends without an ORFS flaring tool.
The O-ring is an additional failure point compared to metal-to-metal JIC.
How to Identify ORFS (SAE J1453) Fittings
Flat face with a visible O-ring groove. Straight threads (not tapered). The nut has a smooth bore for the tube to pass through.
ORFS (SAE J1453) Measurement Tips
ORFS fittings use a captive O-ring that sits in a groove on the flat face of the male fitting. When you tighten the nut, the O-ring compresses against the flat face of the female port. This creates a positive seal that does not rely on thread deformation or metal-to-metal contact. The O-ring does all the sealing work, which is why ORFS can be assembled and disassembled repeatedly without degrading the seal.
What ORFS (SAE J1453) Is Confused With
ORFS and face seal O-ring boss (ORB / SAE J1926) are different standards. ORB uses an O-ring boss on a port with straight threads, while ORFS uses an O-ring on the face of the fitting itself. The O-ring location and the sealing mechanism are different. ORFS is a tube fitting standard. ORB is a port standard. They solve different connection problems.
Data sourced from SAE J1453. Thread dimensions are nominal values. Always verify with a thread identification gauge before making connections.