Specification Grade Silicones

A-A-59588 Silicone for Aerospace and Defense

A‑A‑59588 silicone is a specification grade silicone that’s used in military and aerospace applications. This spec-grade elastomer provides high‑performance sealing and insulation. ElastaPro makes A‑A‑59588 silicone in all classes and grades, and in various durometers, colors, thicknesses. Importantly, these materials are proudly Made in USA in accordance with our AS9100D and ISO 9001:2015 Quality Management System. For traceability, ElastaPro supplies a full Certificate of Analysis (COA) with every batch.

Contact ElastaPro to request a quote or for more information.

What Is A‑A‑59588 Silicone?

A‑A‑59588 is the current U.S. federal specification governing solid silicone rubber used in mission‑critical applications. This specification provides:

  • Excellent high‑ and low‑temperature stability
  • Long‑term compression‑set resistance
  • UV, ozone, and weathering durability
  • Electrical insulation properties
  • Predictable mechanical performance

A‑A‑59588 Silicone Sheet Classes (CL 1, 2, and 3)

ElastaPro makes A‑A‑59588 silicone sheet in Classes 1, 2, and 3.

  • Class 1: A-A-59588 Class 1 is general-purpose silicone sheet for gaskets, enclosure seals, equipment, and electrical insulation pads.
  • Class 2: A-A-59588 Class 1 is a balanced formulation offering improved tensile strength and tear resistance. Typical uses include aerospace components and mechanical equipment.
  • Class 3: A-A-59588 Class 3 is engineered for demanding environments requiring maximum durability and mechanical performance. Applications include defense systems, high‑stress gaskets, dynamic seals, harsh‑environment enclosures.

A‑A‑59588 Silicone Grades (10–70 Shore A)

ElastaPro manufactures A-A-59588 silicones in all standard durometers, or grades.

  • Grade 10 – Very soft
  • Grade 20 – Soft
  • Grade 30 – Medium‑soft
  • Grade 40 – Medium
  • Grade 50 – Medium‑firm
  • Grade 60 – Firm
  • Grade 70 – Very firm

A‑A‑59588 vs. ZZ‑R‑765 (Legacy MIL‑Spec Replacement)

For decades, ZZ‑R‑765 was the primary military specification for silicone rubber. As testing standards and material science advanced, the specification became outdated. The U.S. General Services Administration formally canceled ZZ‑R‑765 and replaced it with A‑A‑59588.

Why A‑A‑59588 Replaced ZZ‑R‑765

A‑A‑59588 was created to:

  • Align with modern ASTM test methods
  • Improve classification of silicone materials
  • Tighten performance tolerances
  • Standardize procurement across suppliers
  • Support modern aerospace and defense requirements

For engineers replacing legacy ZZ‑R‑765 parts, A‑A‑59588 is the approved successor.

Feature ZZ-R-765 A-A-59588
Status Obsolete Current active spec
Test methods Older standards Updated ASTM alignment
Material consistency Variable Tight, repeatable tolerances
Industry use Legacy systems Modern aerospace/defense

A‑A‑59588 vs. A‑A‑55759 — Understanding the Relationship

A‑A‑59588 and A‑A‑55759 are both federal specifications for silicones, but they apply to different material types.

A‑A‑59588

  • Covers solid silicone rubber
  • Used for sheets, rolls, molded parts
  • Ideal for precision gaskets, insulation, and high‑temperature sealing

A‑A‑55759

  • Covers closed‑cell sponge silicone
  • Defines density, compression force, and water‑sealing performance
  • Used for NEMA/IP‑rated enclosures, vibration isolation, and outdoor sealing

How They Work Together

These specifications are complementary:

Technical Advantages of A‑A‑59588 Silicone

  • High‑Temperature Stability: Performs reliably from ‑65°F to +450°F depending on grade.
  • Excellent Compression Set: Maintains sealing force over long service life.
  • Environmental Resistance: Unaffected by UV, ozone, moisture, and weathering.
  • Electrical Insulation: Ideal for aerospace, electronics, and high‑voltage systems.
  • Material Consistency: Tight tolerance control ensures predictable performance in die‑cut and fabricated gaskets.

Available Formats

ElastaPro supplies A‑A‑59588 silicone as:

  • Sheets
  • Continuous rolls
  • Uncured compound
  • Custom colors and thicknesses

Thicknesses typically range from .010” to .500”, with custom options available.

Common Applications

  • Aerospace and defense equipment
  • Industrial machinery
  • Medical and laboratory devices
  • Electronics and power systems
  • High‑temperature gaskets
  • Environmental sealing
  • Vibration isolation

Why Engineers Choose ElastaPro

ElastaPro is a U.S. manufacturer specializing in high‑performance silicone sheet, sponge, foam, and custom compounds. Engineers choose us because we offer:

  • Fast lead times
  • Tight tolerance control
  • Full compliance with A‑A‑59588
  • Custom formulations
  • U.S.‑made quality and consistency

Contact us to request a quote or for more information.