Thread identification
O-Ring Face Seal — ORFS (SAE J1453)
ORFS fittings seal with an O-ring set into a groove on the male's flat face, compressed against the female's flat seat. They are the leak-tightest common hydraulic connection and standard on most late-model excavators and loaders.
Identify it
Four checks at the bench.
- 01
Look at the male face: dead flat with an O-ring groove means ORFS
- 02
The female nose is flat with a smooth internal shoulder — no cone
- 03
Measure thread OD and pitch; ORFS uses fine UN threads one size class 'up' from JIC
- 04
Check the O-ring: 90-durometer, sized per dash — replace it whenever the joint is opened
Don't confuse it with…
- A missing O-ring makes ORFS look like a strange flat JIC — it will never seal without the ring
- Metric flat-face (DIN/Komatsu variants) can look identical; thread pitch tells the truth
- ORB is also O-ring sealed but at a port boss, not a face-to-face union
Reference
Size chart.
| Size | Thread |
|---|---|
| -4 | 9/16-18 UNF |
| -6 | 11/16-16 UN |
| -8 | 13/16-16 UN |
| -10 | 1-14 UNS |
| -12 | 1-3/16-12 UN |
| -16 | 1-7/16-12 UN |
| -20 | 1-11/16-12 UN |
A1 stocks it.
- ORFS Female Swivel Hose EndA1-WB-ORFS
- Interlock ORFS Female SwivelA1-4S-ORFS
- R15 Interlock ORFS FemaleA1-6S-ORFS
- ORFS ↔ JIC Adapter SeriesA1-FA-OJIC
Unsure even after the checks? Bring the fitting to the counter — gauging an unknown thread takes us about a minute. (817) 589-7101.
O-Ring Face Seal — ORFS (SAE J1453) — FAQs
Why do ORFS fittings leak after reassembly?
Almost always a nicked, aged, or missing face O-ring. Replace the ring every time the joint opens; we stock 90-duro kits at the counter.
Can I replace ORFS with JIC?
Only by changing both sides or using an adapter — the threads and sealing methods are incompatible. We stock ORFS-to-JIC adapters for mixed circuits.
Why did equipment makers switch to ORFS?
Elastomeric face seals survive vibration and repeated assembly far better than metal cones, so warranty leak claims drop.