ZZ-R-765 / A-A-59588 CL 2A/2B Solid Silicone | National Silicone

ZZ-R-765 / A-A-59588 CL 2A/2B Silicone

Solid Silicone Sheet

Our ZZ-R-765 / A-A-59588 CL 2A/2B post-cured military specification silicone sheet is designed to be used in applications where higher physical properties and lower compression set are needed.

ZZ-R-765 / A-A-59588 CL 2A/2B Silicone Sheet

Military and Aerospace applications often require silicone with high temperature resistance, crack resistance and flex resistance for various seals and vibration-isolating uses. This general purpose grade silicone sheeting is available in rolls and cut sheets for easy converting and fabricating.

In Stock with Immediate Availability



  • Excellent for seals and gaskets
  • Easy to die-cut
  • Long service life
  • Low compression set
  • UV/Ozone resistant



  • A-A-59588 CL 2A/2B  (formally ZZ-R-765 CL 2A/2B)
  • ASTM D2000 GE



Available in – Continuous rolls or cut sheets
Durometers available – 40, 50, 60, 70, 80
Thicknesses available (in) – 0.03 to 0.500
Typical roll lengths (ft) – 25 to 100
Typical roll widths (in) – 36, 39.4, 47.2, 59.1
Surface finishing – Smooth finish, both sides
Color – Red/orange, grey, black, color matching available



-80°F to +450°F  (-62°C to 232°C)



Hardness, Shore A 40 50 60 70 80 ASTM D2240
Tensile strength, psi 700 700 650 650 650 ASTM D412
Elongation, min % 240 200 150/100 125/80 100/60 ASTM D412
C. set (70h, 150°C), max % 35/25 35/25 40/25 40/25 45/30 ASTM D395B

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National Silicone - 81-SIL-ZZR-SS_202310
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More Information

A-A-59588 CL 2A/2B

  • A-A-59588, formally known as ZZ-R-765, is a defense and aerospace specification.
  • This material is compliant with Federal specification A-A-59588 2A for high temperature resistance in 40, 50, 60, 70, 80 shore A durometer hardness values.
  • Also compliant with Federal specification A-A-59588 2B for high temperature resistance and low compression set in 40, 50, 60, 70, 80 shore A durometer hardness values.
  • A-A-59588 CL 2A/2B is a specification that covers classes of silicone rubber in various grades. Class 2 is a reference to where resistance to extreme high temperature is required to approximately 219°C (425°F) and low temperature resistance to about -62°C (-80°F). Class 2B material also possesses low compression set.



  • ASTM D2000 is a specification for rubber products in automotive applications from the American Society for Testing and Materials.
  • This material passes the ASTM D2000 GE specification for silicone materials.
  • The specification covers the properties of vulcanized rubber materials (natural rubber, reclaimed rubber, synthetic rubbers, alone or in combination) that are intended for, but not limited to, use in rubber products for automotive applications.




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