A variety of heavy-duty, zinc-plated carbon steel SAE O-Ring Boss fittings, engineered for high-pressure hydraulic systems.

Steel SAE O-Ring Boss (ORB) Fittings (SAE J1926)

Q: What's the difference between ORB and NPT threads?

ORB (O-Ring Boss) uses straight threads for clamping force and a dedicated O-ring for a superior, leak-proof seal. NPT (National Pipe Taper) relies on tapered threads deforming to create a seal, which is prone to leaks under vibration. For high-pressure ports, ORB is the modern, more reliable standard.

Q: Are JIC and ORB threads the same?

No. While they may share the same thread size (e.g., 3/4"-16), their sealing methods are different. JIC seals on a 37° metal flare, while ORB uses an O-ring. They are not interchangeable and require a specific adapter to connect.

The Industry Standard for Leak-Proof Hydraulic Ports.

The Engineer's Solution to Leaky Ports.

Chasing leaks from tapered pipe threads is a losing battle against vibration and pressure spikes. The SAE O-Ring Boss (ORB) fitting, governed by the SAE J1926 standard, was engineered to solve this problem. It offers a brutally effective and reliable method for sealing high-pressure hydraulic ports.

The design's brilliance is its simplicity: straight threads provide the mechanical clamping force, while a high-durometer O-ring, compressed into a machined chamfer, provides a dedicated, leak-proof seal. We forge these fittings from high-strength carbon steel and apply a durable zinc plating in-house for robust corrosion resistance. For North American OEMs and distributors, our steel ORB line is the inventory workhorse—a reliable, high-pressure connection that your customers depend on.

SAE O-Ring Boss (ORB) Fitting Catalog (Steel)

37° JIC Male x SAE ORB Male Adapter

Part #: 6400

Straight adapter connecting a female JIC swivel fitting/tube to an SAE O-Ring Boss port. Male JIC x Male ORB ends.

37° JIC Male x SAE ORB Male Adapter Long

Part #: 6400L

Similar to 6400 but with an extended length on the ORB male end for reaching recessed ports.

SAE ORB Male x NPTF Pipe Male Adapter

Part #: 6401

Straight adapter connecting a female NPTF port to an SAE O-Ring Boss port. Male ORB x Male NPTF ends.

SAE ORB Male x 37° JIC Female Swivel Nut Adapter

Part #: 6402

Straight adapter connecting a male JIC flare fitting/tube to an SAE O-Ring Boss port. Male ORB x Female JIC Swivel ends.

SAE ORB Female x NPTF Pipe Male Adapter

Part #: 6404

Straight adapter connecting a male NPTF pipe/fitting into a female ORB threaded cavity (Note: Sealing via ORB threads not standard).

SAE ORB Male x NPTF Pipe Female Adapter

Part #: 6405

Straight adapter connecting a female NPTF pipe/fitting into an SAE O-Ring Boss port. Male ORB x Female NPTF ends.

SAE ORB Male x SAE ORB Male Union

Part #: 6407

Straight union connecting two female SAE O-Ring Boss ports of the same size. Male ORB ends.

SAE ORB Hex Head Plug

Part #: 6408 / 6408H

Seals an unused female SAE O-Ring Boss port. Features an O-ring seal and external hex head for tightening.

SAE ORB Hex Socket Plug

Part #: 6409

Seals an unused female SAE O-Ring Boss port. Features an internal hex (Allen) socket for flush or recessed installation.

SAE ORB Male x SAE ORB Female Reducer/Expander

Part #: 6410

Adapter to connect different ORB thread sizes. Male ORB x Female ORB ends, typically reducing or expanding.

SAE ORB Female x SAE ORB Female Coupler

Part #: 6425

Connects two male ORB fittings. Female ORB threads both ends. (Use limited, sealing relies on male fitting O-rings).

37° JIC Male x SAE ORB Male 90° Elbow

Part #: 6801

90° adapter elbow connecting a female JIC swivel/tube to an SAE O-Ring Boss port. Male JIC x Male ORB ends.

37° JIC Male x SAE ORB Male 90° Elbow Long

Part #: 6801L

Long version of the 90° JIC Male x ORB Male elbow, providing extended reach on one or both ends.

JIC Male x ORB Male 90° Elbow Extra Long

37° JIC Male x SAE ORB Male 90° Elbow Extra Long

Part #: 6801LL

Extra long version of the 90° JIC Male x ORB Male elbow for maximum reach requirements.

37° JIC Male x SAE ORB Male 45° Elbow

Part #: 6802

45° adapter elbow connecting a female JIC swivel/tube to an SAE O-Ring Boss port. Male JIC x Male ORB ends.

SAE ORB Male x NPSM Pipe Female Swivel 90° Elbow

Part #: 6901

90° adapter elbow connecting an ORB port to a male NPSM (straight pipe thread) fitting, featuring a swivel nut.

37° JIC Male x SAE ORB Male Run Tee

Part #: 6804

Tee adapter with two male ORB ends on the run and one male JIC end on the branch.

SAE ORB Male x NPTF Female 90° Elbow

Part #: 6805

90° adapter elbow connecting an ORB port to a male NPTF pipe/fitting. Male ORB x Female NPTF ends.

SAE ORB Male x NPTF Female 90° Long Elbow

Part #: 6805L

Long version of the 90° ORB Male x NPTF Female elbow for extended reach.

SAE ORB Male x NPTF Male 90° Elbow

Part #: 6806

90° adapter elbow connecting an ORB port to a female NPTF port. Male ORB x Male NPTF ends.

SAE ORB Male x SAE ORB Male 90° Elbow

Part #: 6807

90° elbow connecting two female ORB ports. Male ORB ends.

SAE ORB Male x 37° JIC Female Swivel 90° Elbow

Part #: 6809

90° adapter elbow connecting an ORB port to a male JIC flare fitting/tube. Male ORB x Female JIC Swivel ends.

SAE ORB Male x SAE ORB Female 90° Elbow

Part #: 6815

90° elbow adapter with one male ORB end and one female ORB end. (Use may be limited).

SAE ORB Male x NPTF Pipe Female Swivel Adapter

Part #: 6900

Straight adapter connecting an ORB port to a male NPTF pipe/fitting, featuring a swivel nut.

SAE ORB Male x NPSM Pipe Female Swivel 45° Elbow

Part #: 6902

45° adapter elbow connecting an ORB port to a male NPSM pipe/fitting, featuring a swivel nut.

Related Accessories

Steel Case of 288 Assorted O-Rings

Part #: 30002

Convenient assortment case containing various sizes of O-rings suitable for hydraulic adapters, including ORB fittings.

Buna N O-Ring for SAE ORB Adapters

Part #: OB1 Series

Standard Buna-N (Nitrile) O-rings specifically sized for SAE O-Ring Boss ports. Suitable for common hydraulic fluids and moderate temperatures.

Viton® O-Ring for SAE ORB Adapters

Part #: OB2 Series

Viton® (FKM) O-rings sized for SAE ORB ports, offering enhanced chemical resistance and higher temperature tolerance compared to Buna-N.

Connecting ORB Ports to the Rest of Your Hydraulic System

In real machines, SAE ORB ports rarely live alone. They have to tie into JIC tube lines, ORFS hose ends, legacy NPT pipe work or BSPP valve blocks. That’s where the adapters above earn their keep.

JIC to ORB: use straight and elbow adapters like 6400 / 6801 to bring 37° JIC flare lines into ORB ports on pumps and manifolds.
ORB to NPT/NPTF: convert ORB ports to legacy pipe threads with NPT/NPTF pipe fittings when you have existing threaded manifolds or hard piping.
ORB to ORFS: use ORB ports on valves and cylinders, then run ORFS hose assemblies for leak-free performance under vibration.
ORB to BSPP: when tying into European equipment with G ports, combine this ORB range with our BSPP British hydraulic fittings for clean transitions.
When corrosion is the enemy: mirror these connections in our stainless 316 ORB line for marine, chemical and washdown environments.

Engineer's Guide to the SAE J1926 ORB System

The O-Ring Boss system is the preferred choice for high-pressure port connections on pumps, valves, cylinders, and manifolds. Understanding its design principles is key to its successful application.

Sealing Mechanism: Separating Force from Sealing

The ORB system is superior to tapered threads because it separates two critical functions:

Clamping Force: The straight UN/UNF threads are solely for mechanical strength. They pull the fitting down securely and resist vibration, but they perform zero sealing.
Sealing: A 90-durometer Buna-N (or Viton® for higher temperatures) O-ring is compressed into a precision-machined chamfer in the port. This creates a highly reliable, contained seal that is isolated from thread torque.

ORB vs. Other Port Types: A Clear Winner

vs. NPT/NPTF: ORB is significantly more reliable under vibration and pressure cycling. It is reusable, whereas NPT threads deform and lose sealing integrity with each use. ORB also eliminates the need for thread sealants, preventing system contamination.
vs. JIC: JIC is a line-to-line connection (tube to tube), while ORB is a line-to-port connection. They serve different purposes and require an adapter to connect.
vs. ORFS: ORFS is also a superior sealing technology, but it is primarily used for line-to-line connections, excelling in extreme vibration environments. ORB is the go-to for port connections.

Installation Best Practices

Inspect the Port & O-Ring: Ensure the port's machined chamfer is free of debris and scratches. Inspect the O-ring for any nicks or cuts.
Lubricate the O-Ring: Apply a light coating of clean hydraulic fluid or system-compatible grease to the O-ring before installation.
Install Hand-Tight: Screw the fitting into the port by hand until the O-ring makes contact with the port face.
Torque to Specification: Use a torque wrench to tighten the fitting to the SAE-specified value for its size. Overtightening can damage the O-ring or the fitting; under-tightening will result in a leak.

For most hydraulic systems in construction, agriculture, and industrial machinery, zinc-plated steel ORB fittings provide the optimal balance of performance, reliability, and cost.

Straight Answers to Common ORB Questions

What's the difference between ORB and NPT threads?

ORB (O-Ring Boss) uses straight threads solely for mechanical strength and a dedicated O-ring for a superior, leak-proof seal. NPT (National Pipe Taper) relies on tapered threads deforming into each other, which is prone to leaks under vibration and pressure. ORB is the modern, more reliable standard for high-pressure port connections.

Learn more in our complete ORB Guide →

Are JIC and ORB threads the same? Can they connect?

While they often share the same thread size (e.g., 3/4"-16 for -8), their sealing methods are completely different. JIC seals on a 37° metal-to-metal flare, while ORB uses an O-ring. They are not interchangeable and cannot create a seal with each other without a proper adapter (like our Part #6400).

See our JIC vs. ORB vs. ORFS comparison →

When should I choose ORB over ORFS fittings?

Use ORB for connecting a tube or hose fitting into a port on a pump, valve, or cylinder. Use ORFS (O-Ring Face Seal) for connecting two tube or hose ends to each other, especially in high-vibration environments. ORB seals ports; ORFS connects lines.

Read our guide on high-pressure sealing choices →

Do I need sealant or Teflon tape on ORB fittings?

Absolutely not. The O-ring does 100% of the sealing. Adding tape or pipe dope is unnecessary and dangerous, as fragments can break off and contaminate your hydraulic system, leading to pump or valve failure. Simply lubricate the O-ring with clean hydraulic fluid before installation.

Understand the difference between mechanical and sealing threads →

What sizes do SAE ORB fittings come in?

Common sizes are #4 through #20. Threads are straight UN/UNF (e.g., #8 = 3/4"-16). Always match the fitting and port size; sealing occurs at the O-ring/port chamfer, not along the threads.

The Workhorse Fitting Your Inventory Needs.

As a direct manufacturer, we keep these essential steel ORB adapters on the shelf and ready to move. For volume quotes and blanket orders that will actually show up on time, talk to the people who run the machines.

Get a Factory-Direct Quote Need 316L? See Stainless ORB