Hydraulic Fitting Thread ID Chart

What it is

Four connection types cover most North American hydraulic work:

• JIC 37° (SAE J514): straight UN thread, seals on a 37° flare.
• SAE O-ring boss (ORB) (SAE J1926 ports): straight UN thread, seals with an O-ring at the base of the male thread.
• ORFS (SAE J1453): straight UN thread, seals with an O-ring on a flat face.
• NPT / NPTF: tapered pipe thread, seals on the threads.

For JIC, ORB and ORFS the dash number is the tube OD in sixteenths of an inch. For NPT the dash number is the pipe size in sixteenths of an inch.

How to identify

• Tapered thread, no O-ring: NPT or NPTF.
• Straight thread with an O-ring at the base: ORB.
• Straight thread with a 37° cone nose: JIC.
• Straight thread with a flat face and O-ring: ORFS.
• Then measure the thread OD and pitch and match the size in the chart.

Thread size chart

A dash means no common size in that family.

Key points

• JIC and ORB share threads. A JIC male will start into an ORB port but has no O-ring and will leak. Check the seal feature.
• ORFS -4 and JIC -6 both use 9/16-18. Check for a flat face.
• NPT size names are not the measured OD. A 1/4 NPT male measures about 0.54 in across the threads.
• Do not use tape or paste on JIC, ORB or ORFS. They seal on a flare or O-ring.

Common mistakes

• Identifying by thread size only.
• Putting an NPT fitting into an ORB port. The thread forms differ and the port will be damaged.
• Reusing flattened ORB or ORFS O-rings.

Governing standards: SAE J514 (37° flare and ORB fittings); SAE J1926 (straight thread ports); SAE J1453 (ORFS); ANSI/ASME B1.20.1 and B1.20.3 (NPT and NPTF).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.