O Ring Boss Fittings

We offer a comprehensive selection of O-Ring Boss (ORB) fittings, engineered for superior leak-proof hydraulic connections. Our ORB fittings provide excellent sealing integrity and ease of installation, making them ideal for high-pressure applications. Choose Kingdaflex for reliable, high-performance ORB fittings that ensure the durability and efficiency of your hydraulic systems.

Quote Wholesale O Ring Boss Fittings to Delight Your Clients

Material Selection

We offer ORB fittings in a wide array of materials, including various grades of stainless steel, brass, and carbon steel. This allows for optimization based on the fluid being transferred, temperature ranges, and resistance to corrosion or chemical exposure. Selecting the appropriate material ensures compatibility and longevity, crucial for demanding industrial environments and specialized fluid systems.

Surface Finish and Coatings

The surface finish and application of specific coatings are crucial for enhancing durability and performance. We can apply various treatments such as zinc plating, nickel plating, or passivation to improve corrosion resistance, reduce friction, or meet aesthetic requirements. These specialized finishes protect the fittings in harsh operating conditions and extend their service life.

Thread Type and Size

Customization extends to various thread types and sizes, ensuring seamless integration with your existing components. Beyond standard SAE J1926 (UNF threads), we can provide ORB fittings with metric threads or other specialized configurations. This flexibility is vital for international projects or unique equipment designs where standard threading may not suffice, guaranteeing a perfect mechanical fit.

Specialized Configurations and Geometry

We can design and manufacture ORB fittings with unique geometries, including custom angles, multi-port configurations, or integrated features. This allows for optimization of fluid flow, reduced pressure drop, or more compact system designs. Our capability to produce bespoke shapes ensures that even the most complex layout challenges can be addressed efficiently and effectively.

All O Ring Boss Fittings

female o ring boss fittings

female o ring boss fittings

We provide a wide range of female O-Ring Boss (ORB) fittings, essential for creating secure and leak-proof hydraulic connections. These fittings feature a straight thread and a precisely machined chamfer or spotface designed to compress an O-ring, ensuring an exceptional seal when mated with a male ORB counterpart. Our female ORB fittings are available in various materials and configurations to suit diverse industrial applications.

male o ring boss fittings

male o ring boss fittings

We offer a comprehensive range of male O-Ring Boss (ORB) fittings, essential for creating superior leak-proof connections in hydraulic systems. Our male ORB fittings feature a straight thread and an O-ring at the base, ensuring a robust seal when tightened into a female ORB port. These fittings are highly reliable, easy to install, and designed for optimal performance under high pressures.

metric o ring boss fittings

metric o-ring boss fittings

At Kingdaflex, we specialize in high-quality metric O-Ring Boss (ORB) fittings, crucial for reliable hydraulic and fluid power systems across international markets. Our extensive range ensures a perfect fit for metric-threaded ports, offering superior leak prevention through their robust O-ring seal. Trust our metric ORB fittings for optimal performance and compatibility in your specialized machinery and industrial applications.

sae o ring boss fittings

SAE o ring boss fittings

We proudly offer a comprehensive range of SAE O-Ring Boss (ORB) fittings, manufactured to stringent SAE J1926 standards. These fittings provide superior leak-proof connections for hydraulic systems, utilizing a straight thread and an O-ring for robust sealing. Trust Kingdaflex for high-performance ORB fittings that ensure the reliability and integrity of your fluid power applications.

What are O Ring Boss Fittings?

O-Ring Boss (ORB) fittings are a type of hydraulic fitting designed for superior leak control in medium to high-pressure fluid power systems. They feature a male fitting with straight threads and a precisely machined groove at its base, which houses an O-ring. 

The female port has corresponding straight threads and a flat sealing surface or chamfer where the O-ring compresses. This compression of the O-ring against the port’s surface creates a robust, reliable, and leak-proof seal that is highly effective and allows for easy assembly and reusability, unlike tapered thread connections.

how to measure o ring boss fittings?

Accurately measuring O-Ring Boss (ORB) fittings is essential for ensuring a leak-free and secure hydraulic connection. This process requires precise tools and a systematic approach to identify the correct thread size and O-ring specifications, crucial for system integrity.

Step 1: Identify Thread Type and Measure Diameter

First, confirm the fitting is indeed an SAE O-Ring Boss by observing the straight threads and the O-ring groove at the base of the male thread. Then, use a caliper to measure the outside diameter (OD) of the male threads. For female ports, measure the inside diameter (ID) of the threads.

These measurements are crucial for cross-referencing with standard SAE J1926 charts. The nominal size of an ORB fitting is directly related to its thread diameter, unlike NPT. Precise measurement helps avoid misidentification, which can lead to leaks or damage to components.

Step 2: Determine Thread Pitch

After measuring the thread diameter, use a thread pitch gauge to determine the thread pitch. This tool has various blades with different thread counts per inch (TPI). Find the blade that perfectly meshes with the fitting’s threads. This value, combined with the diameter, uniquely identifies the thread.

Knowing the thread pitch is vital for matching the fitting to its corresponding port. SAE ORB fittings typically use UNF (Unified National Fine) threads, and the pitch measurement confirms this standard. Incorrect pitch will prevent proper engagement and sealing.

Step 3: Measure the O-Ring Groove

Use a caliper to measure the dimensions of the O-ring groove on the male fitting. Specifically, measure the major diameter (the diameter of the O-ring when seated) and the width (or depth) of the groove. These measurements are critical for selecting the correct replacement O-ring.

The O-ring’s dimensions must perfectly match the groove for optimal compression and sealing. An undersized O-ring won’t seal, while an oversized one can extrude or be damaged during installation, leading to system failure and potential fluid loss.

Step 4: Get Our Sizing Chart

Once you have accurately measured the thread OD, thread pitch, and O-ring groove dimensions, consult an SAE J1926 (or ISO 11926) sizing chart. This chart will correlate your measurements to a standard ORB fitting size. These charts often list the nominal thread size (e.g., 7/16-20 UNF for a -4 ORB).

Comparing your empirical measurements with published standards is the final verification step. This ensures that you select the exact replacement or new fitting that meets the required specifications for your hydraulic system, guaranteeing compatibility and a reliable, leak-proof connection.

What is the difference between face and boss O-ring?

While both “face O-ring” and “boss O-ring” connections utilize an O-ring to create a seal, the fundamental difference lies in where the O-ring is located and how it is compressed to achieve the seal.

  • O-Ring Face Seal (ORFS) / Face O-ring:

    • In an ORFS fitting, the male connector has straight threads and an O-ring housed in a groove on its flat face (the end of the fitting).
    • The female counterpart has corresponding straight threads and a flat machined surface.
    • When the two fittings are threaded together, the O-ring on the male face is compressed axially against the flat face of the female port. This creates a highly robust, leak-free seal that is excellent for high-pressure applications, especially those with vibration or dynamic forces, as it offers a large sealing surface.
  • O-Ring Boss (ORB) / Boss O-ring:

    • In an ORB fitting, the male connector has straight threads and an O-ring located in a groove at the base of the male thread (the “boss” area).
    • The female port has corresponding straight threads and a chamfered or conical seat at the beginning of its threads.
    • As the male and female fittings are tightened, the O-ring is compressed radially into the chamfered area of the female port, creating a seal. The threads primarily provide the mechanical connection and clamping force, while the O-ring provides the leak-proof seal. ORB fittings are widely used in medium to high-pressure hydraulic systems.

where you can use o ring boss fittings?

O-Ring Boss (ORB) fittings are widely employed in various fluid power applications due to their exceptional ability to create a reliable, leak-proof seal. Their design, which utilizes an O-ring compressed within a groove, makes them particularly well-suited for systems requiring high integrity and easy maintenance.

  • Hydraulic Systems: This is their most common application. ORB fittings are ideal for connecting hoses, tubes, valves, pumps, and cylinders in medium to high-pressure hydraulic circuits found in heavy machinery, agricultural equipment, industrial manufacturing, and mobile hydraulics.
  • Pneumatic Systems: While primarily known for hydraulics, ORB fittings are also used in pneumatic (compressed air) systems where a leak-free seal is critical for efficiency and preventing air loss.
  • Fluid Transfer Lines: Beyond dedicated hydraulic systems, they are found in various fluid transfer lines where reliability is key, such as in some fuel systems, lubrication lines, and coolant circuits.
  • Automotive and Aerospace: In these industries, where vibration and critical safety are paramount, ORB fittings provide a robust connection for various fluid lines, including certain power steering and transmission applications.

what are o ring boss fitting used for?

O-Ring Boss (ORB) fittings are primarily used in fluid power systems where a highly reliable and leak-proof seal is paramount. Their design, incorporating an O-ring at the base of a straight male thread, offers significant advantages over traditional tapered thread connections, making them a preferred choice in numerous demanding applications.

  • Hydraulic Systems: This is the most common and critical application for ORB fittings. They are extensively used to connect hydraulic hoses, tubes, valves, pumps, and cylinders in equipment ranging from heavy construction machinery and agricultural vehicles to industrial manufacturing lines. Their robust sealing mechanism effectively prevents leaks under high pressures and dynamic conditions.
  • Pneumatic Systems: While often associated with hydraulics, ORB fittings are also valuable in compressed air systems. A superior seal is essential for pneumatic efficiency and to prevent air loss, which ORB fittings reliably provide, ensuring optimal performance and reduced energy waste.
  • Automotive Applications: Certain automotive fluid lines, such as specific power steering and transmission cooler lines, utilize ORB fittings due to their excellent resistance to vibration and their ability to maintain a leak-free connection in a constantly moving environment.
  • General Fluid Transfer: Beyond core hydraulic and pneumatic systems, ORB fittings find use in various general fluid transfer lines where integrity is key, such as in lubrication systems, some fuel lines, and coolant circuits, where preventing leaks is important for safety and operational efficiency.
  • Vacuum Systems: In certain vacuum applications, ORB fittings can also be employed to ensure a tight seal that prevents atmospheric air from entering the system, maintaining the desired vacuum level.