Overview
JIC – Joint Industry Council – SAE J514, ISO 8434-2
UN – Unified National – SAE J1926, ISO 11926-2
JIC & UNO (O-Ring Boss) thread forms are the same (ASME B1.1). The method of sealing differs.
Sealing Methods
JIC 37° Flare
Male has a 37° seat. This seat is the sealing face (face that stops leaks). When screwed into a JIC female, the 37° male seat seals against the 37° seat of the female.
For joining tube together or to adapt a tube to another fitting – a JIC tube nut and sleeve can be used. The tube will need flaring to 37°, and the end result is a female JIC end.
UNO (O-Ring Boss)
Although the thread is the same as JIC, the sealing method is different. All UNO males will have an O-ring – this O-ring is the seal, and it sits in the female port spot face.
For elbows and tees, there is an added backup washer and lock nut on the fittings to allow for different orientation.
Identification Table
| Dash Size | Tube OD (inch) | Thread Size | Threads Per Inch | OD of Thread (mm) |
|---|---|---|---|---|
| -2 | 1/8″ | 5/16-24 | 24 | 7.94 |
| -3 | 3/16″ | 3/8-24 | 24 | 9.53 |
| -4 | 1/4″ | 7/16-20 | 20 | 11.11 |
| -5 | 5/16″ | 1/2-20 | 20 | 12.70 |
| -6 | 3/8″ | 9/16-18 | 18 | 14.29 |
| -8 | 1/2″ | 3/4-16 | 16 | 19.05 |
| -10 | 5/8″ | 7/8-14 | 14 | 22.23 |
| -12 | 3/4″ | 1-1/16-12 | 12 | 26.99 |
| -16 | 1″ | 1-5/16-12 | 12 | 33.34 |
| -20 | 1¼″ | 1-5/8-12 | 12 | 41.28 |
| -24 | 1½″ | 1-7/8-12 | 12 | 47.63 |
| -32 | 2″ | 2-1/2-12 | 12 | 63.50 |