Radium Engineering -8AN ORB to -6AN Male Fitting | Fuel & Oil Line Adapter

The Radium Engineering -8AN ORB to -6AN Male Fitting is a precision-machined adapter fitting designed for use in high-performance fuel, oil, and coolant line routing applications — providing a reliable, leak-free connection between an -8AN O-ring boss (ORB) port and a -6AN male flare fitting. Machined to Radium Engineering's exacting quality standards, this fitting is a purpose-built solution for builders who need to adapt between ORB-ported components — such as fuel rails, oil coolers, and engine block ports — and -6AN hose end fittings in a custom plumbing system. A small but critical component for any high-performance fuel or oil system build where fitment precision and leak-free reliability are non-negotiable.

Key Features:

• -8AN ORB inlet — O-ring boss (ORB) port connection provides a positive, leak-free seal via a compressed O-ring at the port face — superior to tapered thread connections for high-pressure fuel and oil applications
• -6AN male outlet — standard -6AN male flare fitting outlet for direct connection to -6AN hose ends and fittings throughout the plumbing system
• Precision-machined construction — machined to Radium Engineering's quality standards for accurate thread form, correct AN flare angle, and consistent O-ring seating surface
• Versatile application — suitable for fuel, oil, and coolant line routing wherever an -8AN ORB port needs to be adapted to a -6AN hose end connection
• Radium Engineering quality — manufactured by one of the most respected names in high-performance fuel system components for import and domestic performance platforms

Technical Details:

• Inlet Connection: -8AN O-ring boss (ORB) — seals via O-ring compression at the port face
• Outlet Connection: -6AN male flare — 37° JIC/AN flare standard
• Thread Pitch: -8AN ORB: 3/4–16 UNF; -6AN male: 9/16–18 UNF
• Seal Type: O-ring boss (ORB) inlet seal; AN flare outlet seal
• Suitable Fluids: Fuel, oil, coolant (verify material compatibility for your specific application)

Specifications:

• Brand: Radium Engineering
• Part Number: RAD14-0151
• Inlet: -8AN ORB (O-ring boss)
• Outlet: -6AN male flare
• Construction: Precision-machined
• Application: Fuel, oil, and coolant line routing — high-performance plumbing systems

Fitment & Compatibility:

• Compatible with any component featuring an -8AN ORB (O-ring boss) port — including fuel rails, oil coolers, oil filter adapters, engine block ports, and other ORB-ported fittings
• Outlet connects to any standard -6AN hose end or -6AN female fitting in the plumbing system
• Note: Verify O-ring material compatibility with your specific fluid (fuel, oil, or coolant) before installation. Replace the O-ring if reusing the fitting after removal. Use a quality AN-compatible O-ring rated for your fluid type.

What's Included:

• Radium Engineering -8AN ORB to -6AN male fitting — RAD14-0151 (1 piece)
• O-ring (verify inclusion with product — replace O-ring if reusing after removal)

Installation Notes:

• Apply a light film of clean oil or assembly lubricant to the O-ring before installation to prevent pinching and ensure correct seating
• Thread the ORB fitting into the port by hand until the O-ring contacts the port face, then tighten to the manufacturer's specified torque — do not overtighten, as this can damage the O-ring and port face
• Connect the -6AN male outlet to the mating -6AN hose end and tighten to standard AN fitting torque specification
• Pressure-test the completed plumbing system before returning to full-load operation — check all fittings for leaks at operating pressure
• Inspect the O-ring for damage or deformation at each service interval and replace as needed

Why O-Ring Boss (ORB) Fittings?

O-ring boss (ORB) fittings are the preferred connection standard for high-performance fuel and oil system ports — providing a positive, leak-free seal via a compressed O-ring at the port face rather than relying on tapered thread interference (NPT) or flare-to-flare contact (AN). ORB connections are less sensitive to thread damage and overtightening than NPT fittings, and provide a more reliable seal under the pressure cycling and thermal expansion of a high-performance engine environment. Many high-quality fuel rails, oil coolers, and engine components use ORB ports as their primary connection standard — making adapter fittings like this Radium Engineering piece an essential part of any custom plumbing build.

Why Radium Engineering?

Radium Engineering is one of the most respected names in high-performance fuel system engineering — with a product lineup spanning fuel surge tanks, fuel rails, fuel pressure regulators, catch cans, and the full range of fittings, adapters, and hardware needed to build a complete, reliable high-performance fuel system. Radium's engineering philosophy emphasizes precision manufacturing, correct material selection, and system-level thinking — their fittings and adapters are not generic hardware store components, but purpose-engineered parts manufactured to the tolerances and material specifications that high-performance fuel and oil systems demand. For builders who want every component in their fuel or oil system to meet the same standard as the major components, Radium Engineering fittings are the correct choice.

Perfect For:

• Custom fuel system builds requiring an adapter between an -8AN ORB fuel rail or component port and a -6AN hose end
• Oil cooler plumbing where an -8AN ORB port needs to be adapted to a -6AN line in the oil cooling circuit
• Engine swap builds where factory ORB ports need to be integrated into a custom AN-fitting plumbing system
• Any high-performance plumbing application requiring a reliable, precision-machined -8AN ORB to -6AN male adapter

Pro Tip: When building a custom fuel or oil plumbing system, standardize on a single AN size throughout the system wherever possible to minimize the number of adapter fittings required. Where size transitions are necessary — such as this -8AN ORB to -6AN adapter — use quality precision-machined fittings like Radium Engineering's to ensure consistent thread form and sealing surface quality at every connection point in the system.

Note: Verify O-ring material compatibility with your specific fluid before installation. Replace the O-ring if reusing the fitting after removal. Pressure-test all connections before returning to full-load operation.