The application of fluorosilicone oil in medium-resistant lubrication for military equipment primarily relies on its unique molecular structure—a polysiloxane main chain modified with trifluoropropyl groups.  It combines the wide temperature range stability of organosilicon with the chemical inertness of fluorinated compounds, providing irreplaceable lubrication and sealing functions in extreme military environments.

Core Application Scenarios
Aerospace Power Systems: Used in fuel line seals, fuel tank liners, hydraulic system bellows, and pump diaphragms of aircraft engines, resisting JP-8 aviation fuel, high-energy propellants, and high-temperature fluids, preventing leakage and material swelling.
Missile and Rocket Propulsion Systems: Used as a dynamic sealing lubricant in solid/liquid fuel delivery systems, resisting strong oxidizing media suchs as hydrazine and nitrogen tetroxide, ensuring the reliability of ignition and thrust control systems.
Electronic and Sensor Systems: Used as a base oil for high-insulation lubricating grease in micro-bearings and electrical contact points of missile guidance modules, radar transceiver units, and battlefield communication equipment, providing moisture resistance, corrosion resistance, and low friction characteristics.
Ground Combat Equipment Hydraulic Mechanisms: Applied to the sealing and lubrication of tank transmission systems, artillery elevation mechanisms, and armored vehicle suspension systems, resisting high-load reciprocating motion and complex contamination environments of battlefield mud, sand, and oil. Chemical Resistance Performance List
Fluorosilicone oil exhibits excellent chemical stability and physical durability in military environments against the following media:

Medium Type | Resistance Performance | Temperature Range | Reference Basis
JP-8 Aviation Fuel | Volume change <2% after 500 hours of immersion, no significant degradation in hardness and tensile strength | -60℃ ~ 200℃ |
Hydraulic Oil (Mineral-based) | No swelling, no precipitation, stable lubricating film | -40℃ ~ 180℃ |
Chlorinated Hydrocarbon Solvents (e.g., trichloroethane) | Excellent chemical inertness, molecular structure remains intact | -68℃ ~ 232℃ |
Methanol-Gasoline Mixture (85:15) | Vulcanized rubber property retention >95%, suitable for high-alcohol fuel environments | -50℃ ~ 180℃ |
High Vacuum Environment | Extremely low volatility (<5% @200℃/4h), no oil mist contamination | -80℃ ~ 250℃ |
Note: Fluorosilicone oil has poor resistance to ketones, esters, and strong alkaline media (such as ammonia and amines) and should be avoided.

Technical Standards and Specifications
Chinese Military Standard (GJB): Although no specific standard numbered "GJB XXXX-XXXX Fluorosilicone Lubricant" was found, its application fully complies with the core requirements of GJB 1200 "General Specification for Military Lubricants" regarding "medium resistance, wide temperature range, and long service life," and it is often used as a preferred alternative to traditional mineral oils and fluororubber seals.
International Standard (MIL-SPEC): No specific US military standard number was found, but the US Department of Defense has widely adopted fluorosilicone-based lubricants in the sealing systems of equipment such as the F-35 and AH-64.  Its technical parameters are included in supplier technical agreements (such as the DuPont MOLYKOTE® series), forming a de facto industry standard. Performance Comparison Advantages
Comparison Object | Advantages of Fluorosilicone Oil | Limitations of Fluorosilicone Oil
Perfluoropolyether (PFPE) | 30%-50% lower cost, lower low-temperature brittleness temperature (-89℃ vs -40℃), easier to apply | Slightly inferior high-temperature oxidation resistance, prone to slow oxidation in environments above 250℃ for extended periods
Fluororubber (FKM) | As a liquid lubricant, it is suitable for dynamic components (bearings, valve cores), not just static seals; enables integrated "lubrication + sealing" | Lower mechanical strength than solid fluororubber, not suitable for high-pressure static sealing
Ordinary Silicone Oil | More than 10 times improvement in fuel and solvent resistance, significantly enhanced chemical stability | Higher cost than ordinary silicone oil, not suitable for applications where non-polar media requirements are not demanding