A-A-59588

ElastaPro makes A-A-59588 silicone in all classes and grades, and in a choice of durometers, thicknesses and colors. Choose solid silicone sheet or uncured silicone compound. ElastaPro’s A-A-59588 silicones are Made in USA in accordance with our AS9100D and ISO 9001:2015 Quality Management System. For traceability, we supply a Certificate of Analysis (COA) with every batch.

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A-A-59588 Silicones from ElastaPro

The table below contains the Commercial Item Description (CID) for A-A-59588 silicones. ElastaPro can supply you with these materials in all classes and grades. Contact us for a quote.

Class		Grade*
1A	Low temperature resistant	40, 50, 60, 70, 80
1B	Low temperature resistant and low compression set at high temperature	40, 50, 60, 70, 80
2A	High temperature resistant	25, 40, 50, 60, 70, 80
2B	High temperature resistant and low compression set	25, 40, 50, 60, 70, 80
3A	Low temperature resistant Tear resistant Flex-fatigue resistant	30, 50, 60
3B	Tear resistant Flex-fatigue resistant	30, 50, 60, 70, 80

 *For most classes, grades have a hardness of ±5 Shore A. For classes 2A Grade 30, and 3A Grade 30the A-A-59588 spec lists +5, -10 durometer instead.

A-A-59588 Class 1A Silicone: Grades 40, 50, 60, 70, 80 

A-A-59588 CL 1A silicones resist extreme low temperatures. The spec defines this as approximately -100ºF (-73ºC). A-A-59588 CL 1A silicones also resist high temperatures to approximately 425ºF (219ºC), but for a shorter length of service than CL 2 materials.

ElastaPro offers A-A-59588 CL 1A silicones in GR 40, 50, 60, 70, and 80.

A-A-59588 Class 1B Silicone: Grades 40, 50, 60, 70, 80

A-A-59588 CL 1B silicones resist extreme low temperatures. The spec defines this as approximately -100ºF (-73ºC). A-A-59588 CL 1B silicones also resist high temperatures to approximately 425ºF (219ºC), but for a shorter length of service than CL 2 materials. The difference between CL 1A and CL 1B is that CL 1B materials also have low compression set at high temperatures.

ElastaPro offers A-A-59588 CL 1B silicones in GR 40, 50, 60, 70, and 80.

A-A-59588 Class 2A Silicone: Grades 25, 40, 50, 60, 70, 80

A-A-59588 CL 2A silicones resist high temperatures. The spec defines this as approximately 425ºF (219ºC). CL 2A materials also have low temperature resistance, which the spec lists as approximately -80ºF (-62ºC).

ElastaPro offers A-A-59588 CL 2A silicones in GR 25, 40, 50, 60, 70, 80.

A-A-59588 Class 2B Silicone: Grades 25, 40, 50, 60, 70, 80

A-A-59588 CL 2B silicones resist high temperatures. The spec defines this as approximately 425ºF (219ºC). CL 2B materials also have low temperature resistance, which the spec lists as approximately -80ºF (-62ºC). CL 2B materials also have low compression set.

ElastaPro offers A-A-59588 CL 2B silicones in GR 25, 40, 50, 60, 70, 80.

A-A-59588 Class 3A Silicone: Grades 30, 50, 60

A-A-59588 CL 3A silicones resist extreme low temperatures, tearing, and flexing. The spec defines this low temperature resistance as approximately -103ºF (-75ºC). CL 3A silicones also resist high temperatures to approximately 400ºF (204ºC).

ElastaPro offers A-A-59588 CL 3A silicones in GR 30, 50, and 60.

A-A-59588 Class 3B Silicone: Grades 30, 50, 60, 70, 80

A-A-59588 CL 3B silicones are high-strength silicones that resist low temperatures, tearing, and flexing. The spec defines this low temperature resistance as -94ºF -70ºC, which is not as extreme as with CL 3A materials. For CL 3B silicones, the high-end of the temperature range is the same: 400ºF (204ºC). 

ElastaPro offers A-A-59588 CL 3B silicones in GR 30, 50, 60, 70, 80. 

A-A-59588 Silicone Sheet Sizes from ElastaPro

ElastaPro offers A-A-59588 solid silicone sheet in rolls so that these products are continuous lengths. They come in standard sizes like 36″ and 48″ wide, and in linear lengths up to and exceeding 300 yards in some cases. ElastaPro also provides cut sheets in standard dimensions such as 12″ x 12″, 24″ x 24″, 36″ x 36″, and 48″ x 48″. In addition, we offer custom sheet sizes.

• Widths: Standard widths include 36″ (914.4 mm) and 48″ (1219.2 mm). Custom widths up to 62″ (1574.8 mm) are available. We calendar up to the some of the widest widths in the industry.
• Lengths: Linear lengths up to and exceeding 300 yards (274.32 m)
• Thicknesses: Solid silicone sheet from ElastaPro comes in thicknesses between .005” to .500” (.13 mm to 12.7 mm).
• Cut Sheets: Standard sizes include 12″ x 12″, 24″ x 24″, 36″ x 36″, and 48″ x 48″.  Custom sheet sizes are available.

ElastaPro also offers uncured silicone compound.

FAQs about A-A-59588 Silicones

What is A‑A‑59588 silicone?

A‑A‑59588 is a U.S. General Services Administration (GSA) Commercial Item Description (CID) that classifies silicone rubber into six classes and multiple durometer‑based grades. It replaced the older ZZ‑R‑765 military specification and is widely used in aerospace and defense applications.

What classes and grades are available under A‑A‑59588?

The specification includes six classes—1A, 1B, 2A, 2B, 3A, and 3B—each with defined performance characteristics such as low‑temperature resistance, high‑temperature resistance, tear resistance, and compression‑set performance. Grades correspond to durometer values ranging from 25 to 80 depending on class.

What are the temperature ranges for A‑A‑59588 silicones?

Temperature performance varies by class:

• Class 1A & 1B: approx. −100°F to 425°F
• Class 2A & 2B: approx. −80°F to 425°F
• Class 3A: approx. −103°F to 400°F
• Class 3B: approx. −94°F to 400°F

These ranges are defined in the CID and reflected in ElastaPro’s product offerings.

What is the difference between A‑A‑59588 and ZZ‑R‑765?

A‑A‑59588 is the modern, active specification that supersedes the obsolete ZZ‑R‑765 standard. It aligns with updated ASTM test methods, tightens tolerances, and improves material classification for aerospace and defense procurement. Some legacy drawings still reference ZZ‑R‑765, but A‑A‑59588 is the approved successor.

What is the difference between A‑A‑59588 and A‑A‑55759?

Both specifications cover solid silicone materials and share the same classes and grades. However, A‑A‑55759 additionally specifies thickness and color, making it more prescriptive for certain applications.

What forms does ElastaPro supply for A‑A‑59588 silicone?

ElastaPro manufactures A‑A‑59588 silicone as:

• Solid silicone sheet (rolls or cut sheets)
• Uncured silicone compound
• Custom widths up to 62″
• Thicknesses from 0.005″ to 0.500″
• Roll lengths up to 300+ yards

All materials are produced in the U.S. under AS9100D and ISO 9001:2015 quality systems.

Does ElastaPro provide certification with A‑A‑59588 materials?

Yes. Every batch includes a Certificate of Analysis (COA) for full traceability, supporting aerospace and defense documentation requirements.

Can A‑A‑59588 silicone be used to replace legacy ZZ‑R‑765 parts?

Yes. A‑A‑59588 is the designated replacement for ZZ‑R‑765 and is suitable for updating legacy components to current standards. Engineers should match class and grade equivalents when transitioning.

What applications commonly use A‑A‑59588 silicone?

A‑A‑59588 silicones are widely used in:

• Aerospace gaskets and seals
• Defense equipment
• High‑temperature insulation
• Low‑temperature sealing environments
• Flex‑fatigue‑resistant components (Classes 3A and 3B)

These applications leverage the spec’s tight tolerances and predictable performance.

How do I choose the right class and grade for my application?

Selection depends on required temperature range, compression‑set performance, tear resistance, and durometer. For example:

• Extreme low‑temp: Class 1A or 1B
• High‑temp: Class 2A or 2B
• High tear/flex: Class 3A or 3B

ElastaPro can assist with class/grade matching for aerospace and defense requirements.

Ask ElastaPro for A-A-59588 Silicone

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.