M83248/2-906 - Preformed Packing Fluorocarbon O-Ring

M83248/2-906 – Mil-Spec High-Pressure Fluorocarbon O-Ring

Available now on the Airparts.aero Marketplace.

Overview

The M83248/2-906 is a high-performance, mil-spec preformed packing (O-ring) manufactured in strict accordance with the military specification MIL-DTL-83248/2. This specification defines a specialized fluorocarbon (FKM, Viton® type) elastomer engineered for the demanding requirements of aerospace fluid systems, particularly featuring improved performance at low temperatures. The -906 dash number identifies it as a standard size for creating a high-pressure boss gasket seal on -6 (3/8 inch) straight thread tube fittings.

Designed for exceptional reliability, this O-ring is a critical sealing component in high-pressure hydraulic, fuel, lubrication, and pneumatic systems across a wide range of military and civilian aircraft. Its 90-durometer hardness provides superior resistance to extrusion, while the FKM material offers excellent compatibility with most petroleum-based fluids. As a fundamental component in countless flight-critical systems, the use of a fully certified and traceable M83248/2-906 O-ring is an essential element of safe and airworthy maintenance.

Key Features

• Mil-Spec Certified: Manufactured and tested in strict accordance with MIL-DTL-83248/2, guaranteeing material composition, dimensional accuracy, and performance.

• Advanced Fluorocarbon FKM Material: Provides excellent resistance to petroleum-based hydraulic fluids (e.g., MIL-PRF-5606), engine oils, and aviation fuels.

• Improved Low-Temperature Performance: The M83248/2 compound is specifically formulated to maintain its sealing properties at the low temperatures encountered during cold-soak conditions at high altitude.

• 90 Durometer Hardness: The high hardness (Shore A) provides superior resistance to extrusion and physical damage in high-pressure applications (up to 3,000 PSI).

• High-Pressure Boss Seal: The -906 size is specifically designed to seal straight thread tube fittings against a flat boss, a common connection method for pumps, actuators, and valves.

Technical Specifications

• Part Number / Specification: M83248/2-906

• Component Type: O-Ring / Preformed Packing (Boss Gasket Seal)

• OEM Manufacturer: Certified Mil-Spec Manufacturer

• Material: Fluorocarbon Rubber (FKM), 90 Durometer (Shore A)

• Size Standard: AS568 Dash Number -906 (for a 9/16-18 straight thread boss, corresponding to a -6 or 3/8" tube OD fitting).

• Governing Specification: MIL-DTL-83248/2

• Typical Operating Temperature Range: -40°F to 400°F (-40°C to 204°C)

Aircraft Compatibility

• Universal Aerospace Application: This is a standard mil-spec component used on a vast range of aircraft where a seal with these specifications is required. It is found on aircraft manufactured by:

  • Boeing, Lockheed Martin, Textron Aviation (Cessna, Beechcraft), Piper, Gulfstream, Bombardier, and many others.

Note: The correct O-ring material and part number must be verified in the specific aircraft or component maintenance manual. O-ring selection is flight-critical and system-dependent.

Applications

• Hydraulic Systems: Sealing high-pressure lines and components, such as brake systems, landing gear actuators, flight control actuators, and power packs.

• Fuel Systems: Used on fuel pumps, selector valves, and filter housings where a high-pressure, fuel-resistant seal is required.

• Engine & Propeller Systems: Sealing lubrication lines, propeller governors, and other engine accessories that utilize straight thread boss fittings.

Why Choose M83248/2-906?

An O-ring is one of the most critical and least expensive components in any aircraft fluid system. Using a generic, non-certified part of unknown origin is an unacceptable risk. An incorrect o-ring may lack the specified material properties, leading to swelling, hardening, or chemical degradation. It may lack the correct durometer, resulting in extrusion failure under pressure, or it may lack the low-temperature characteristics, causing it to shrink and leak at altitude. The failure of a single o-ring can lead to a catastrophic, in-flight leak of flammable hydraulic fluid or fuel. The certified M83248/2-906 is a low-cost guarantee of material integrity, traceability, and safety.

The engineering principle behind the specification of a 90 durometer elastomer for the M83248/2-906 is rooted in the physics of high-pressure sealing and the prevention of extrusion. In a boss fitting, system pressure energizes the O-ring, forcing it against the walls of the gland. Simultaneously, this pressure attempts to push the solid elastomer material through the microscopic clearance between the two metal components (the extrusion gap). A softer material (e.g., 70 durometer) would deform more easily and be "nibbled" away as it is forced into this gap, leading to rapid seal failure. The 90 Shore A hardness of the M83248/2 compound provides a high modulus of elasticity and significant resistance to this plastic deformation. This allows the O-ring itself to bridge the extrusion gap under high pressure (typically up to 3,000 PSI) without requiring the additional complexity and weight of a separate, rigid anti-extrusion backup ring.

Note: The M83248/2-906 is a flight-critical seal. Never reuse O-rings. Always install a new, certified O-ring whenever a fitting is disconnected. Inspect the sealing surfaces on the fitting and the boss for any nicks, scratches, or corrosion before installation. Lightly lubricate the new O-ring with clean system fluid to prevent damage during installation. Ensure the O-ring is not twisted in the gland.

Documentation

• MIL-DTL-83248/2: The military detail specification sheet defines all material, dimensional, and testing requirements for this O-ring and is publicly available through the Defense Logistics Agency ASSIST database and various online mil-spec libraries.