?unique=f365869)
M83248/1-024 – Aerospace Fluorocarbon (Viton™) O-Ring Packing
Available now through the AirParts Aero marketplace.
Overview Section
The M83248/1-024 is a high-performance Fluorocarbon (FKM) O-ring designed specifically for aerospace fluid systems. Manufactured to the MIL-R-83248 military specification (Type 1, Class 1), this "Preformed Packing" is the industry standard for applications requiring maximum resistance to high temperatures and chemically aggressive fluids.
As a -024 dash size, this O-ring features a mid-sized diameter with a slim 1/16-inch (0.070") cross-section. This configuration is commonly utilized in fuel system manifolds, hydraulic fittings, and engine accessory interfaces where a reliable seal is needed in a space-constrained environment.
Key Features Section
Extreme Chemical Resistance: Specifically engineered to resist degradation when exposed to Jet-A, 100LL, synthetic turbine oils, and various hydraulic fluids.
High-Temperature Stability: Maintains its sealing properties in environments ranging from -15°F to +400°F ($-26°C$ to $+204°C$).
75 Durometer (Shore A): Provides the ideal balance of hardness and flexibility, offering resistance to "extrusion" under pressure while ensuring a gas-tight seal.
Low Compression Set: Formulated to resist permanent deformation, ensuring the O-ring "springs back" to maintain a seal during thermal cycling.
Ozone and UV Immunity: Unlike standard Nitrile, the Fluorocarbon material is virtually unaffected by atmospheric aging, making it suitable for both internal engine use and external airframe components.
Precision AS568 Sizing: Manufactured to strict aerospace tolerances for a predictable fit in standard narrow-width glands.
Technical Specifications Section
| Specification | Detail |
| Military Standard | M83248/1 (AS83248/1) |
| Dash Size | -024 |
| Material | Fluorocarbon (FKM / Viton™) |
| Inside Diameter (ID) | 1.114 in (28.30 mm) |
| Outside Diameter (OD) | 1.254 in (31.85 mm) |
| Cross-Section (W) | 0.070 in (1.78 mm) |
| Hardness | 75 Shore A |
| Color | Black |
Aircraft Compatibility Section
The M83248/1-024 is used extensively throughout the turbine and high-performance piston fleets:
Pratt & Whitney PT6A: Found in various external oil line fittings and accessory mounting flanges.
Honeywell TFE731: Utilized for fuel manifold seals and secondary air system couplings.
Beechcraft King Air / 1900: Standard for hydraulic system port seals and fuel system unions.
Cessna Citation Series: Used in environmental control system (ECS) valves and hydraulic reservoir interfaces.
Technical Applications & Safety
In aerospace applications, the O-ring creates a seal by being compressed within a "gland." Because the -024 size is relatively thin (1/16"), it is critical that the mating metal surfaces are free of scratches.
Safety Warning: Do not substitute with Nitrile (Buna-N). While an MS28775-024 (Nitrile) may look identical, it will fail rapidly if exposed to the high heat or synthetic oils that the M83248/1 is designed for. Always verify the Cure Date on the packaging. Although Fluorocarbon has a very long shelf life, O-rings showing any signs of surface "bloom" or stiffness should be discarded.
Technical Engineering Insight
The engineering value of the M83248/1-024 lies in its Molecular Stability. In high-pressure turbine environments, "outgassing" and chemical "leaching" can cause lower-grade seals to shrink, leading to sudden leaks. The M83248/1 compound is chemically inert to most aviation aromatics. Because the -024 has a thin cross-section ($0.070"$), the Gland Volume Fill is vital. Per aerospace standards, the O-ring should occupy approximately 75% of the gland volume to allow for the thermal expansion of the rubber without causing the housing to over-stress or "lock" the assembly.
Installation & Maintenance Addendum
Avoid Spiral Failure: Because of the large ID and thin cross-section, this O-ring can easily twist. Use a specialized lubricant like Parker Super O-Lube to ensure the ring "slides" into place.
Visual Inspection: Use a 10x loop to inspect the O-ring for "nicks" before installation. In thin-section O-rings, a microscopic cut can lead to a high-pressure bypass.
Tooling: Use only non-marring (plastic or brass) tools for removal. A steel screwdriver will gouge the aluminum gland, creating a permanent leak path.
