Thread identification
JIC 37° Flare (SAE J514)
JIC fittings seal metal-to-metal on a 37° flare seat and use UNF straight threads. They are the most common hydraulic connection on North American equipment, identified by the female's flared cone and the absence of any O-ring.
Identify it
Four checks at the bench.
- 01
Look into the female nose: a smooth internal cone with no O-ring means a flare seat
- 02
Check the seat angle with a gauge — 37° (JIC), not 45° (automotive/refrigeration flare)
- 03
Measure thread OD with calipers and match to the JIC size chart
- 04
Count threads per inch with a pitch gauge and confirm against the chart
Don't confuse it with…
- SAE 45° flare uses the same thread sizes in several cases — the seat angle is the only difference, and mixing them weeps under pressure
- SAE O-ring boss (ORB) shares UNF threads but seals with an O-ring at a port face, not a cone
- BSPP 60° cone looks similar by eye; thread pitch reveals it (metric-ish Whitworth pitches)
Reference
Size chart.
| Size | Thread |
|---|---|
| -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 |
| -20 | 1-5/8-12 UN |
A1 stocks it.
- JIC 37° Female Swivel Hose EndA1-WB-J37F
- JIC 37° Male Rigid Hose EndA1-WB-J37M
- JIC 37° Female Swivel — 45° ElbowA1-WB-J37F45
- JIC 37° Female Swivel — 90° ElbowA1-WB-J37F90
Unsure even after the checks? Bring the fitting to the counter — gauging an unknown thread takes us about a minute. (817) 589-7101.
JIC 37° Flare (SAE J514) — FAQs
Do JIC fittings need thread sealant?
No. JIC seals on the 37° cone seat, not the threads. Tape or paste on JIC threads does nothing and can shed debris into the system.
Are JIC and AN fittings the same?
Dimensionally interchangeable — AN is the tighter-tolerance aerospace spec, JIC the industrial one. For shop hydraulics, JIC is what you're buying.
How tight should a JIC fitting be?
Torque to spec or use the flats-from-finger-tight method (typically 1/4 to 1/2 turn past snug depending on size). Overtightening cracks flares.