A-A-59588 Silicone for Aerospace and Defense
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.
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?
A-A-59588 is a U.S. General Services Administration (GSA) specification that groups compliant silicones into alphanumeric classes and numbered grades. The classes are 1A, 1B, 2A, 2B, 3A, and 3B. The grades are durometer-based. Class is abbreviated as CL. Grade is abbreviated as GR.
Is A-A-59588 the same as AA 59588?
A-A-59588 is sometimes written as AA-59588 or even AA 59588. The correct way to write this specification is A-A-59588.
What happened to ZZ-R-765E?
For decades, ZZ‑R‑765E was the primary military specification for silicone rubber. As testing standards and material science advanced, however, ZZR7655E (as it’s sometimes written) became outdated.
The U.S. General Services Administration formally canceled ZZ‑R‑765 and replaced it with commercial item description (CID) A‑A‑59588 on January 12, 2001. Some part drawings may still contain ZZ-R-765, however. There are also instances where
Why was A-A-59588 created?
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
What’s the difference between ZZ-R-765 and A-A-59588?
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 |
What’s the difference between A‑A‑59588 and A‑A‑55759?
A‑A‑59588 and A‑A‑55759 are both specifications for solid silicones. They contain the same classes and grades. Where these two specs differ is that A-A-55759 also calls out a thickness and color.
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.
