MIL-DTL-25988 Fluorosilicone Sheeting & Compounds | Type I & Type II
Engineered for extreme fuel, oil, and solvent resistance, ElastaPro MIL-DTL-25988 fluorosilicone (FVMQ) delivers uncompromised sealing performance in aggressive military and commercial aerospace environments. Manufactured in the USA at our AS9100D and ISO 9001:2015 certified facility, our MIL-DTL-25988 (formerly MIL-R-25988 / AMSR-25988) materials are available in continuous sheet rolls, cut sheets, and uncured compounds across all classes and grades.
What is MIL-DTL-25988 (FVMQ) Fluorosilicone Specification?
MIL-DTL-25988 (often cited as MIL-R-25988 or SAE AMS-R-25988) is the military specification governing fluorosilicone rubber elastomers designed for high-temperature service in contact with hydrocarbon fuels, jet fuels (JP-4, JP-8, JP-10), synthetic lubricants, hydraulic fluids, and ozone.
By combining the wide temperature flexibility of silicone with the chemical inertness of fluorocarbons, fluorosilicone (FVMQ) retains its elastomeric properties across continuous temperatures from -70°F to +392°F (-57°C to +200°C), with short-term excursions up to +450°F (+232°C).
MIL-DTL-25988 Material Matrix: Types, Classes & Grades
Selecting the correct type, class, and durometer is critical to ensure proper seal compression, tear resistance, and fluid immersion performance:
| Classification | Material Form / Application | Available Grades (Shore A) | Primary Performance Attribute |
|---|---|---|---|
| Type I | O-Rings, Molded Shapes, Compression Seals | Grade 50, 60, 70, 80 | Low compression set in fuel/oil immersion |
| Type II | Sheet, Molded Strip, Die-Cut Flat Gaskets | Grade 40, 50, 60, 70, 80 | Sheet calendar stability & high tear resistance |
| Class 1 | General Purpose Fuel/Oil Resistant | 40 to 80 Shore A | Standard low-temp capability (-70°F) |
| Class 2 | High Tear & Flex Fatigue Resistant | 50, 60, 70 Shore A | Elevated tensile and tear propagation resistance |
Chemical & Fuel Resistance Profile
ElastaPro MIL-DTL-25988 fluorosilicone sheeting is specifically compounded to resist degradation when exposed to aggressive aerospace fluids and harsh ambient conditions:
- Aviation Fuels: Jet-A, JP-4, JP-5, JP-8, JP-10, and high-octane aviation gasolines (AvGas).
- Synthetic Lubricants & Oils: MIL-L-7808 and MIL-L-23699 turbine engine oils.
- Hydraulic Fluids: Skydrol, silicate ester fluids, and mineral-based hydraulic oils.
- Solvents & Hydrocarbons: Benzene, toluene, xylene, and non-polar petroleum solvents.
- Environmental Exposure: Exceptional resistance to ozone, UV radiation, weathering, and high-altitude corona discharge.
Available Product Formats, Thicknesses & PSA Options
- Continuous Sheet Rolls: Standard roll widths of 12″, 24″, 36″, and custom widths up to 48″ for continuous roll-to-roll die cutting and waterjet converting.
- Precision Thicknesses: Precision calendered from 0.010″ to 0.500″ (0.25 mm to 12.7 mm).
- Uncured Fluorosilicone Compounds: Pig-slabs and continuous strips available for compression molders and extruders needing target-viscosity formulations.
- Pressure Sensitive Adhesive (PSA): Factory-applied solvent-resistant acrylic or fluorosilicone PSA backing for rapid release-liner assembly.
- Colors: Standard blue/gray and red, with custom color compounding available upon request.
Frequently Asked Questions About MIL-DTL-25988 Fluorosilicone
What is the difference between standard silicone and MIL-DTL-25988 fluorosilicone?
Standard silicone (VMQ) swells and degrades rapidly when exposed to fuels, oils, or solvents. MIL-DTL-25988 fluorosilicone (FVMQ) incorporates trifluoropropyl side chains that make the polymer highly resistant to hydrocarbon fuels, jet fuels, and synthetic lubricants while maintaining silicone’s wide operating temperature range.
What is the difference between MIL-DTL-25988 Type I and Type II?
Type I is formulated specifically for molded shapes, O-rings, and molded seals requiring ultra-low compression set. Type II is formulated specifically for flat sheet rolls, cut gaskets, and strip material where tear resistance and dimensional calendering tolerances are paramount.
What specs superseded MIL-R-25988 and AMSR-25988?
MIL-DTL-25988 is the current active Department of Defense detail specification. It superseded the older military specification MIL-R-25988. SAE AMS-R-25988 is the equivalent commercial aerospace standard adopted by SAE International.
Does ElastaPro supply full material certification (COA) for MIL-DTL-25988 orders?
Yes. Every batch of ElastaPro fluorosilicone is supplied with a comprehensive Certificate of Analysis (COA) verifying durometer, tensile strength, elongation, volume swell after fluid immersion, and compression set per applicable ASTM D2000 and MIL-DTL-25988 test methods.
