FS6400 ORFS to O-Ring Stud Straight

Direct ORFS-to-ORB Connection

FS6400 provides a simple connection between two commonly used hydraulic sealing systems:

Male ORFS → Straight Adapter → Male ORB

The ORFS end is designed to mate with a female ORFS connection, while the O-Ring Boss end installs into a compatible female ORB port.

This makes the fitting useful when hydraulic equipment uses ORB ports but the connected hose or tube assembly uses ORFS fittings.

ORFS O-Ring Face Seal

The ORFS side uses a flat-face O-ring sealing system.

The O-ring sits at the face of the male fitting and seals against the mating female ORFS connection. This design is widely used in hydraulic systems where dependable leakage control is important.

The sealing face and O-ring should be kept clean and inspected before installation. A damaged, contaminated, or incorrectly seated O-ring can compromise the connection.

Male O-Ring Boss Stud

The opposite side of FS6400 uses a Male O-Ring Boss (ORB) stud.

Unlike tapered pipe threads, ORB uses a straight thread with an O-ring to create the primary seal against the port. This makes it a useful choice for hydraulic valves, manifolds and equipment designed with ORB ports.

The ORB end should always be matched to the correct port size and thread specification.

Standard Straight Configuration

FS6400 has a straight body, making it suitable for inline connections where no directional change is required.

The compact configuration is useful when:

• ORFS and ORB ports are positioned in line
• A direct hydraulic transition is needed
• Space around the connection is limited
• You want to avoid unnecessary elbows
• A simple hose-to-port connection is required

If additional reach is needed, the FS6400-L Long version is a separate option. FS6400 itself is the standard straight configuration.

Steel Construction for Hydraulic Service

The FS6400 series is manufactured in steel, while comparable specifications identify forged carbon steel construction with a trivalent zinc protective finish.

This construction is suitable for hydraulic equipment exposed to:

• High operating pressure
• Vibration
• Mechanical shock
• Pressure cycling
• Heavy equipment movement
• Industrial working conditions

The protective zinc finish helps improve resistance to corrosion during demanding service.

High-Pressure Hydraulic Performance

Gear House Hydraulics lists FS6400 for working pressures up to 6,000 PSI, with pressure capability dependent on tube and fitting size. The collection also identifies the series for applications containing continuous mechanical shock.

For extreme-pressure systems at 5,000 PSI or above, the complete hydraulic assembly should be checked for compatibility, including the selected fitting size, hose or tubing, mating components and seals.

ORFS to ORB for Mixed Hydraulic Systems

Hydraulic equipment often combines different connection styles depending on the manufacturer, hose assembly and component design. FS6400 makes it easier to connect an ORFS hose or tube assembly to an ORB port without converting the connection to NPT or another thread type.

Typical connection layout:

ORFS Hose / Tube Assembly → FS6400 → ORB Port

This direct transition keeps the hydraulic connection compact and avoids unnecessary connection points.

Common Applications

FS6400 ORFS to ORB straight adapters are commonly suited for:

• Hydraulic hose assemblies
• Hydraulic manifolds
• Hydraulic valves
• Pumps
• Cylinders
• Mobile hydraulic equipment
• Construction machinery
• Agricultural equipment
• Industrial hydraulic systems
• OEM hydraulic assemblies
• Hydraulic repair and maintenance

They are particularly useful where a hydraulic component has an ORB port and the required hose or tube connection uses ORFS.

FS6400 Features & Benefits

• Male ORFS × Male ORB
• Straight inline configuration
• O-ring face seal on ORFS side
• O-ring sealing on ORB side
• Steel construction
• Forged design
• Trivalent zinc protective finish
• Working pressures up to 6,000 PSI, size dependent
• Suitable for high-pressure hydraulic applications
• Designed for applications with mechanical shock
• Multiple equal and reducing sizes
• Compact connection between ORFS and ORB systems

FS6400 vs. FS6400-L

Both fittings connect Male ORFS to Male ORB, but their body lengths are different.

FS6400: Standard straight adapter for normal inline installations.

FS6400-L: Long straight adapter for applications where additional reach or clearance is required.

If the available installation space does not require extra length, the standard FS6400 is the straightforward choice.

How to Choose the Right FS6400 Size

Before ordering, check both sides of the hydraulic connection.

1. Identify the ORFS size
Match the Male ORFS end with the compatible Female ORFS connection.

2. Identify the ORB size
Confirm the Male ORB stud matches the equipment's female ORB port.

3. Check whether a reducing adapter is required
FS6400 is available in equal and reducing combinations, so the two connection sizes do not necessarily need to be the same.

4. Verify the pressure requirement
Make sure the selected size and complete hydraulic assembly are rated for the required working pressure.

5. Confirm the configuration
FS6400 is a straight adapter. If the hydraulic line needs to turn 45° or 90°, choose the appropriate elbow configuration instead.

Why Choose Gear House Hydraulics?

Gear House Hydraulics offers FS6400 in a broad range of ORFS-to-ORB sizes for hydraulic systems that need a reliable, compact connection between two different sealing systems.

With steel construction, ORFS O-ring face sealing, ORB O-ring sealing and a straight adapter design, FS6400 is a practical choice for hydraulic hose assemblies, manifolds, valves, mobile equipment and industrial fluid power systems.

Choose the correct ORFS and ORB sizes for your equipment and verify the complete system requirements before installation.

Frequently Asked Questions

What is an FS6400 fitting?

FS6400 is a straight hydraulic adapter that connects a Male ORFS fitting to a Male O-Ring Boss (ORB) port.

What does FS6400 connect?

It connects a Female ORFS connection to a Female ORB hydraulic port using a Male ORFS × Male ORB adapter.

Is FS6400 a straight fitting?

Yes. FS6400 is a straight inline adapter and does not change the direction of the hydraulic line.

What sealing does FS6400 use?

The ORFS side uses an O-ring face seal, while the ORB side uses an O-ring Boss sealing arrangement.

What material is FS6400 made from?

Gear House Hydraulics lists the collection as Steel. Comparable manufacturer specifications list FS6400 as forged carbon steel with trivalent zinc plating.

What pressure can FS6400 handle?

Gear House Hydraulics lists working pressures up to 6,000 PSI, depending on tube and fitting size.

Is FS6400 suitable for high-pressure hydraulic systems?

Yes. It is intended for high-pressure applications and is listed for applications involving continuous mechanical shock.

What sizes are available?

The collection includes multiple combinations from 1/4" through 1-1/2", including equal and reducing sizes.

What is the difference between FS6400 and FS6400-L?

FS6400 is the standard-length straight adapter, while FS6400-L is the long version for installations requiring additional reach.

Can FS6400 connect different size ports?

Yes. The FS6400 range includes reducing combinations, allowing different ORFS and ORB sizes to be connected.

Is FS6400 suitable for hydraulic hose assemblies?

Yes. FS6400 is well suited for hydraulic hose assemblies where an ORFS connection needs to transition to an ORB port.

What should I check before ordering FS6400?

Confirm the ORFS size, ORB size, thread compatibility, straight configuration and required pressure rating before selecting the fitting.