Specification Grade Silicones

Military Silicones and Fluorosilicones

Military silicones and fluorosilicones from ElastaPro meet U.S. military specifications (MIL-SPEC) and standards. We supply a full Certificate of Analysis (COA) with every batch and welcome your questions about the origins of our raw materials.

At ElastaPro, we believe that supply chain literacy and friendly nation sourcing are part of the job. That’s why we work closely with military buyers to help them understand not just what they’re specifying, but where it comes from and how secure that supply chain really is.

Whether you need solid or cellular sheets, continuous rolls, or uncured compound, ElastaPro manufacturers military silicones and fluorosilicones in Santa Fe Springs, California (USA) in accordance with our ISO 9001:2015 and AS99100D certified quality management system.

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What Makes It a Military Silicone or Fluorosilicone?

Military silicones (VMQ), phenyl silicones (PVMQ) and fluorosilicones (FVMQ) are formulated and manufactured to meet U.S. military specifications and standards for products such as:

  • Seals
  • Gaskets
  • O-rings
  • Electrical insulation
  • Vibration damping

The main difference between military silicones and fluorosilicones is that fluorosilicones offer greater resistance to fuel, oils, and other chemicals.  Fluorosilicones tend to be more expensive, but they’re required for some military applications.

Collectively, these high-performance materials are also called MIL-SPEC silicones. They meet military detail specifications (MIL-DTL) or military standards (MIL-STD) and may carry designations such as MIL-R for military rubber products.

Some military silicones and fluorosilicones meet other specs and standards. Examples include AMS silicones and AMSR25988 fluorosilicones. SAE International, a standards development organization, defines Aerospace Material Specifications (AMS) that the U.S. military uses.

Types of Military Silicones and Fluorosilicones

ElastaPro makes military silicones and fluorosilicones that meet these specifications.

The sections below provide brief descriptions with links to pages that contain additional information.

Note: Obsolete specs appear in parentheses but still appear on some older part drawings.

A-A-55759 (ZZ-R-765)

A-A-55759 silicone meets the requirements of a U.S. government specifications that supersedes ZZ-R-765. A-A-55759 silicones meet the A-A-59588 requirements, but the A-A-55759 specification also calls out a thickness and a color.

A-A-59588 (ZZ-R-765)

A-A-59588 silicone meets the requirements of a U.S. government specification that supersedes ZZ-R-765. ElastaPro makes A-A-59588 1A, 1B, 2A/2B, 3A, and 3B silicones.

AMS 3325 and AMS 3326

AMS 3325 fluorosilicone is resistant to fuel and oils and available in a hardness of 55-65 durometer (Shore A). AMS 3326 was superseded by AMS3325, and its requirements are now part of this newer standard.

AMS 3327

AMS 3327 fluorosilicone is designed for high-temperature applications in fuel systems and lubricants. It offers excellent resistance to fuels and oils. AMS 3327 fluorosilicone is available in a 70-80 durometer (Shore A).

AMS 3345

AMS 3345 silicone silicone is a high-strength, methyl phenyl vinyl silicone (PVMQ) used in low-temperature and aircraft piston engine oil environments. It specifies a Shore A hardness of 50 durometer (45 to 55 range).

AMS 3357

AMS 3357 silicone silicone meets an AMS standard for a silicone rubber (VMQ) that is designed to be resistant to aircraft piston engine lubricating oils. It has good compression set resistance and a durometer range of 65-75 (Shore A).

AMS-R-25988 (MIL-DTL-25988)

AMS-R-25988 fluorosilicone meets the requirements of an SAE International specification that supersedes MIL-DTL-25988 and is used by the U.S. military. ElastaPro makes Type 2, Class 1 materials in Grades 40, 50, 60, and 70.

ASTM D6576 (MIL-R-6130, MIL-R-46089)

ASTM D6576 silicone meets an ASTM International specification for flexible cellular rubber that is chemically blown. It replaces the two obsolete military specifications: MIL-R-6130 and MIL-R-46089. ASTM D6576 covers closed-cell medium-density silicone sponge sheet, which ElastaPro provides.

MIL-STD-417 TA

MIL-STD-417 TA silicone silicone meets the requirements of a U.S. military standard for solid elastomer materials. The “TA” designation refers to silicones and is followed by a three-digit number. ElastaPro makes MIL-STD-417 TA silicones that range from TA 405 to TA810.

MIL-STD-670 TE12

MIL-STD-670 TE12 silicone foam meets the requirements of a U.S. military standard for a closed-cell medium-density silicone foam for seals and gaskets. The TE12 designation indicates a specific firmness and density within the larger standard.

WS14644

WS14655 silicone meets the requirements of a U.S. Navy specification for electrically conductive silicone rubber compounds. ElastaPro makes Type III high conductivity, carbon black filled materials. Applications include EMI gaskets, anti-static components, and conductive pads and seals.

FAQs about Military Silicones and Fluorosilicones

What is military solid silicone sheet used for in aerospace and defense applications

Military solid silicone sheets are used for high‑reliability sealing, gasketing, vibration isolation, and thermal insulation in military aircraft, ground vehicles, naval systems, and electronics. Engineers specify these materials when they need tight tolerance control, long‑term durability, and proven performance under harsh environmental conditions.

How do military silicone sheets differ from commercial grade silicone sheets?

Military silicones are manufactured to strict mechanical, thermal, and environmental requirements defined by U.S. military standards.

Compared to commercial silicone, MIL‑Spec grades offer:

  • More consistent durometer and tensile properties
  • Lower compression set
  • Better resistance to temperature cycling
  • Verified performance under vibration, humidity, and aging This ensures predictable behavior in mission‑critical systems.

What temperature range do military silicone sheets support

Most military silicone sheets operate from –65°F to +400°F (–54°C to +204°C). High‑temperature formulations may extend beyond this range. These materials maintain elasticity at low temperatures and resist thermal degradation at elevated temperatures, making them suitable for engine compartments, avionics bays, and exterior military environments.

Are military silicone sheets compatible with fuels, oils, or hydraulic fluids

Standard military silicone is not fuel‑resistant. It should not be used in direct contact with Jet‑A, JP‑8, diesel, lubricants, or hydraulic fluids such as Skydrol. For chemical‑exposed environments, engineers should specify fluorosilicone (e.g., AMS‑R‑25988 or MIL‑DTL‑25988), which provides excellent resistance to fuels and oils.

Can military silicone sheets be fabricated into custom gaskets and seals

Yes. Military silicone sheets can be converted into precision gaskets, pads, and seals using waterjet cutting, die cutting, slitting, and bonding. These materials are ideal for continuous‑loop gaskets, enclosure gaskets, and high‑temperature sealing applications where dimensional accuracy and long‑term reliability are essential.

Additional Resources

See these pages for information about dimensions, durometers, colors, and added-value services such as roll slitting and pressure-sensitive adhesive (PSA) lamination.

Contact ElastaPro for military silicones and fluorosilicones you can count on.