BSP, JIC or ORFS: identifying hydraulic fittings
You can tell a BSP, JIC or ORFS fitting apart by three things: the seal, the thread angle and the size. JIC seals on a 37° cone, ORFS with an O-ring in a flat face, and BSP with a sealing washer or a 60° cone. BSP has a 55° thread angle, JIC and ORFS have 60°. A concrete example: if a male thread measures 20.96 mm with 14 threads per inch, it is 1/2" BSP. If it measures 19.05 mm with 16 threads per inch and has a 37° cone, it is JIC -8 (3/4"-16 UNF).
Identify your fitting in 4 steps
- Look at the seal: an angled cone (37° or 60°), a flat face with an O-ring, or a sealing washer under the hex.
- Measure the outside diameter of the male thread with a caliper.
- Determine the pitch with a thread gauge: count the threads per inch (inch threads) or measure the pitch in millimetres (metric threads).
- Look up the combination of seal, diameter and pitch in the tables below.
Comparison: BSP, JIC, ORFS and metric
| Type | Standard | Thread | Seal | How to recognise it |
|---|---|---|---|---|
| BSPP (parallel) | ISO 228-1 (G thread), ISO 1179 | Whitworth, 55°, parallel | Sealing washer or O-ring, or 60° cone in the swivel nut | Straight thread, 55°, inch size |
| BSPT (tapered) | ISO 7-1 (R thread) | Whitworth, 55°, tapered 1:16 | Seals on the thread (with tape or sealant) | Thread tapers |
| JIC | SAE J514, ISO 8434-2 | UN/UNF, 60° | Metal to metal on a 37° cone | Angled 37° cone, UNF thread |
| ORFS | SAE J1453, ISO 8434-3 | UN/UNF, 60° | O-ring in a flat face | Flat face with an O-ring in a groove |
| Metric (DIN) | DIN 2353, ISO 8434-1 | Metric fine thread, 60° | 24° cone with cutting ring | Thread in mm, L or S series |
BSP sizes: outside diameter and threads per inch
| BSP size | Outside diameter (mm) | Threads per inch |
|---|---|---|
| 1/8" | 9.73 | 28 |
| 1/4" | 13.16 | 19 |
| 3/8" | 16.66 | 19 |
| 1/2" | 20.96 | 14 |
| 5/8" | 22.91 | 14 |
| 3/4" | 26.44 | 14 |
| 1" | 33.25 | 11 |
| 1 1/4" | 41.91 | 11 |
| 1 1/2" | 47.80 | 11 |
JIC and ORFS: sizes by dash number
| Size (dash) | JIC thread | JIC outside diameter (mm) | ORFS thread | ORFS outside diameter (mm) |
|---|---|---|---|---|
| -4 | 7/16"-20 | 11.11 | 9/16"-18 | 14.29 |
| -6 | 9/16"-18 | 14.29 | 11/16"-16 | 17.46 |
| -8 | 3/4"-16 | 19.05 | 13/16"-16 | 20.64 |
| -10 | 7/8"-14 | 22.23 | 1"-14 | 25.40 |
| -12 | 1 1/16"-12 | 26.99 | 1 3/16"-12 | 30.16 |
| -16 | 1 5/16"-12 | 33.34 | 1 7/16"-12 | 36.51 |
| -20 | 1 5/8"-12 | 41.28 | 1 11/16"-12 | 42.86 |
| -24 | 1 7/8"-12 | 47.63 | 2"-12 | 50.80 |
Watch out: these look alike
- JIC -6 and ORFS -4 both have a 9/16"-18 thread. They screw together, but they do not seal: JIC seals on a 37° cone, ORFS with an O-ring in a flat face. Always check the seal, not just the thread.
- 1/2" BSP (20.96 mm, 14 threads per inch) and ORFS -8 (20.64 mm, 16 threads per inch) differ by only 0.3 mm in diameter. The difference is in the pitch and the thread angle.
- JIC (37°) looks like SAE 45° flare, which is mainly used in refrigeration and automotive systems. The two are not interchangeable.
Frequently asked questions
Can I connect a JIC fitting to an ORFS fitting?
No. Even if the thread fits, as with JIC -6 and ORFS -4 (both 9/16"-18), the connection will not seal: JIC seals on a 37° cone and ORFS with an O-ring in a flat face. Use an adapter from one system to the other.
What is the difference between BSPP and BSPT?
BSPP has a parallel thread and seals with a sealing washer, O-ring or cone. BSPT has a tapered thread (1:16) and seals on the thread itself, usually with tape or sealant. Both have a 55° thread angle.
What does -8 mean for JIC or ORFS?
The dash number gives the tube outside diameter in sixteenths of an inch. So -8 stands for 8/16" = 1/2" tube. The thread belongs to that number: JIC -8 has 3/4"-16 UNF, ORFS -8 has 13/16"-16.
Is a 1/2" BSP thread actually 1/2 inch in diameter?
No. 1/2" is the nominal pipe size. The outside diameter of a 1/2" BSP male thread is 20.96 mm, with 14 threads per inch.
How do I recognise a metric DIN fitting?
A metric DIN fitting (DIN 2353, ISO 8434-1) has a thread in millimetres and seals with a 24° cone and cutting ring. It comes in a light (L) and a heavy (S) series.
Where can I find the right fitting or hose?
You will find all fittings and adapters under Fittings. You can build a hose with the right fittings in the Hose Generator. Ready-made hoses are under Hydraulic hoses.
Not sure which fitting you have? Contact us and we will be happy to help.