JIC Fitting Thread Sizes: Dash Sizes, Tube OD & SAE J514 Data
JIC (SAE J514) uses 37-degree flare threads with a metal-to-metal seal per SAE J514. Thread dimension table and identification tips below.
Thread Sizes
| Dash Size | Tube OD | Thread |
|---|---|---|
| -2 | 1/8" | 5/16-24 UNF |
| -3 | 3/16" | 3/8-24 UNF |
| -4 | 1/4" | 7/16-20 UNF |
| -5 | 5/16" | 1/2-20 UNF |
| -6 | 3/8" | 9/16-18 UNF |
| -8 | 1/2" | 3/4-16 UNF |
| -10 | 5/8" | 7/8-14 UNF |
| -12 | 3/4" | 1-1/16-12 UN |
| -16 | 1" | 1-5/16-12 UN |
| -20 | 1-1/4" | 1-5/8-12 UN |
| -24 | 1-1/2" | 1-7/8-12 UN |
| -32 | 2" | 2-1/2-12 UN |
The most common hydraulic fitting in North America. JIC fittings use a 37-degree flare seat and straight threads. The flare provides a metal-to-metal seal without an O-ring, which makes JIC fittings reusable and field-serviceable. You can take them apart and reassemble them without replacing seals.
When to Use JIC
Mobile equipment and construction machinery.
JIC handles most hydraulic applications from 500 to 5,000 psi.
Choose JIC when you need a connection you can disassemble in the field without carrying spare O-rings.
It is the default choice in North American fluid power.
Where JIC Falls Short
The flare quality depends on your tube preparation.
A bad flare leaks.
Not as vibration-resistant as ORFS.
For pressures above 6,000 psi, look at ORFS or welded connections.
How to Identify JIC Fittings
Look for the 37-degree flare on the tube end and straight threads on the body. Often stamped with dash sizes (-4, -6, -8).
Measurement Tips
When measuring a JIC fitting, the dash size corresponds to the tube OD in sixteenths of an inch. A -8 fitting is for 8/16 inch (1/2 inch) tubing. The thread size does not directly match the tube size. A -8 JIC has a 3/4-16 thread, not a 1/2 inch thread. This catches people who try to measure the thread and match it to the tube size.
What JIC Gets Confused With
JIC and AN (Army-Navy) fittings are dimensionally identical and fully interchangeable. The difference is only in the specification they were manufactured to. AN fittings meet military inspection standards but the threads, angles, and dimensions are the same as SAE J514. If your supplier only stocks AN fittings, they will work in a JIC application and vice versa.
JIC (SAE J514): Common Questions
What thread is a -8 JIC fitting?
3/4-16 UNF. A -8 JIC fitting connects to 1/2 inch OD tubing. The dash number represents the tube OD in sixteenths of an inch, so -8 means 8/16 = 1/2 inch.
Are JIC and AN fittings the same?
Functionally interchangeable for most applications. Both use a 37-degree flare angle. AN (Army-Navy) fittings have tighter military tolerances on the flare surface finish and dimensional accuracy, but the thread and seal geometry is identical. In non-aerospace applications, JIC and AN fittings mate without issues.
Can you connect JIC to NPT?
Not directly. JIC has straight threads with a 37-degree flare seal. NPT has tapered threads that seal by thread deformation. The thread forms are incompatible. You need a JIC-to-NPT adapter fitting that has JIC male on one end and NPT male on the other, or vice versa. For a full breakdown of the differences, see the JIC vs NPT comparison. Use the Adapter Finder tool to find the exact adapter for your JIC-to-NPT connection.
Reference data only. Verify thread dimensions with a thread identification gauge before making connections. Working with pressurized hydraulic systems involves serious injury risks including high-pressure injection, burns, and crushing hazards. This site does not replace manufacturer specifications, proper training, or employer safety procedures. See full terms of use.
Data sourced from SAE J514, SAE J1926. Thread dimensions are nominal values. Always verify with a thread identification gauge before making connections.