Specification Grade Silicones

A-A-59588 Military Specification Silicone Sheets & Uncured Compounds

ElastaPro manufactures a complete line of A-A-59588 (formerly ZZ-R-765) solid silicone sheeting and uncured silicone compounds for high-reliability aerospace, defense, and industrial applications. Published as a Commercial Item Description (CID) by the U.S. General Services Administration (GSA), A-A-59588 establishes strict physical, mechanical, and thermal performance parameters for elastomeric materials used across defense supply chains.

A-A-59588 covers six distinct material classes categorized by low-temperature flexibility, high-temperature stability, compression set resistance, and tear/flex-fatigue resistance. Every batch of ElastaPro’s specification grade silicones are Made in the USA under our ISO 9001:2015 and AS9100D certified quality management system and supplied with a full Certificate of Analysis (COA). ElastaPro also makes A-A-55759 silicones.

Need A-A-59588 Mil-Spec Silicone Sheeting or Slit Rolls?

We supply continuous rolls, pre-cut solid sheets, and custom uncured compounds across all classes (1A, 1B, 2A, 2B, 3A, 3B) with low minimum order quantities and fast lead times.

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A-A-59588 Material Class & Durometer Matrix

Selecting the proper A-A-59588 class depends on your operating temperature profile, flexural fatigue requirements, and sealing pressure limits:

Class Primary Performance Characteristic Durometer Grades (Shore A) Temperature Range
Class 1A Extreme Low-Temperature Resistance 40, 50, 60, 70, 80 -100°F to +425°F (-73°C to +219°C)
Class 1B Extreme Low Temp + Low Compression Set 40, 50, 60, 70, 80 -100°F to +425°F (-73°C to +219°C)
Class 2A Extreme High-Temperature Resistance 25, 40, 50, 60, 70, 80 -80°F to +425°F (-62°C to +219°C)
Class 2B High Temp + Low Compression Set 25, 40, 50, 60, 70, 80 -80°F to +425°F (-62°C to +219°C)
Class 3A Extreme Low Temp + High Tear & Flex Resistance 30, 50, 60 -103°F to +400°F (-75°C to +204°C)
Class 3B High Tear Strength & Flex-Fatigue Resistance 30, 50, 60, 70, 80 -95°F to +400°F (-70°C to +204°C)

Note: Classes 3A and 3B represent high-strength formulations that pass the DeMattia Flex Resistance Test (ASTM D813) for dynamic sealing applications.

Legacy Specification Conversion: A-A-59588 vs. ZZ-R-765

A-A-59588 directly superseded federal specification ZZ-R-765E. When converting legacy engineering drawings or NSN procurement callouts:

  • ZZ-R-765 Class 1A / 1B: Converts directly to A-A-59588 Class 1A / 1B (Phenyl-based low-temp silicone).
  • ZZ-R-765 Class 2A / 2B: Converts directly to A-A-59588 Class 2A / 2B (General-purpose high-temp silicone).
  • ZZ-R-765 Class 3A / 3B: Converts directly to A-A-59588 Class 3A / 3B (High-strength / tear-resistant silicone).

Key Aerospace & Defense Applications

  • Aircraft Environmental Seals: Door, window, and canopy gaskets exposed to extreme high-altitude thermal cycling.
  • Dynamic Flex Mounts: Vibration dampers, engine mounts, and exhaust hangers subject to repetitive dynamic movement.
  • Enclosure Seals: Weatherproof environmental gaskets for military electronics, radar systems, and communication gear.
  • Custom Converted Parts: Precision die-cut and waterjet-cut gaskets supplied with optional factory-applied Pressure Sensitive Adhesive (PSA).

In addition to A-A-55759 silicones, ElastaPro makes many other types of aerospace silicones and military silicones.

Frequently Asked Questions About A-A-59588 Silicone

What is A-A-59588 silicone, and how does it relate to ZZ-R-765?

A-A-59588 is the current U.S. General Services Administration (GSA) Commercial Item Description defining solid silicone rubber materials for military and aerospace use. It completely supersedes the older federal specification ZZ-R-765, maintaining identical performance class structures while updating quality and testing benchmarks.

Which A-A-59588 class should I specify for dynamic flexing applications?

For dynamic applications where gaskets endure mechanical stress, vibration, or repetitive bending, choose Class 3A or Class 3B. Both classes are formulated for high tear strength and must pass the DeMattia Flex Resistance Test to prevent crack initiation and propagation. Select Class 3A if your operating environment reaches sub-zero temperatures down to -103°F (-75°C).

What is the difference between “Class 2A” and “Class 2B” silicone?

While both Class 2A and Class 2B offer continuous resistance to elevated temperatures up to 425°F (219°C), Class 2B is specifically formulated to deliver low compression set. This makes Class 2B the superior choice for static flange gaskets that require long-term sealing pressure without suffering permanent deformation over time.

Can ElastaPro supply A-A-59588 sheets with adhesive backing?

Yes. ElastaPro supplies A-A-59588 solid silicone sheeting in continuous rolls or cut sheets with factory-applied Pressure Sensitive Adhesive (PSA) backings. Options include general-purpose acrylic adhesives or high-temperature silicone adhesives protected by a peel-off liner for easy gasket conversion and assembly.