Class 1A and Class 1B
Class 1A and Class 1B silicones are best for extreme low temperature environments, defined as -73°C (-100°F). These silicones can also handle high temperatures, up to 219°C (425°C), but they don’t last as long as Class 2 materials when consistently exposed to heat in service. At high temperatures, Class 1B silicones have low compression set.
Class 2A and Class 2B
Class 2A and Class 2B silicones are best for high temperatures, up to 219°C (425°C). They have less low temperature resistance than Class 1 silicones and generally can’t resist temperatures lower than -62°C (-80°F). Class 2B silicones have low compression set.
Class 3A
Class 3A silicones are resistant to tearing, flexing, and extreme temperatures ranging from -75°C (-103°F) to 204°C (400°F). Common applications for Class 3A silicones are exhaust hangars and engine mounts.
Class 3B
Class 3B silicones share many properties with Class 3A, including excellent resistance to tearing, flexing, and high heat. However, Class 3B’s low temperature resistance range is limited to -70°C (-95°F). Common applications for Class 3B silicones include vibration mounts and seals for windows and aircraft doors.
A-A-59588B provides a framework for selecting and qualifying silicone gasket materials for demanding military and aerospace applications. Understanding the performance characteristics of each material class helps support appropriate material selection and long-term sealing reliability.
Please note: The information outlined above is to be used as a reference for A-A-59588B. Please refer to GSA for full details and the most current revision.
Class 1A and Class 1B silicones are best for extreme low temperature environments, defined as -73°C (-100°F). These silicones can also handle high temperatures, up to 219°C (425°C), but they don’t last as long as Class 2 materials when consistently exposed to heat in service. At high temperatures, Class 1B silicones have low compression set.
Class 2A and Class 2B
Class 2A and Class 2B silicones are best for high temperatures, up to 219°C (425°C). They have less low temperature resistance than Class 1 silicones and generally can’t resist temperatures lower than -62°C (-80°F). Class 2B silicones have low compression set.
Class 3A
Class 3A silicones are resistant to tearing, flexing, and extreme temperatures ranging from -75°C (-103°F) to 204°C (400°F). Common applications for Class 3A silicones are exhaust hangars and engine mounts.
Class 3B
Class 3B silicones share many properties with Class 3A, including excellent resistance to tearing, flexing, and high heat. However, Class 3B’s low temperature resistance range is limited to -70°C (-95°F). Common applications for Class 3B silicones include vibration mounts and seals for windows and aircraft doors.
How Smithers Supports A-A-59588B
Smithers supports defense manufacturers and suppliers through independent testing and technical assessment for silicone elastomer materials used in demanding aerospace and defense applications. Our specialists help evaluate material performance, environmental durability, compression set, and long-term reliability to support qualification activities and generate trusted technical evidence for defense applications. Explore our Defense Materials and Qualification capabilities to learn more.A-A-59588B provides a framework for selecting and qualifying silicone gasket materials for demanding military and aerospace applications. Understanding the performance characteristics of each material class helps support appropriate material selection and long-term sealing reliability.
Please note: The information outlined above is to be used as a reference for A-A-59588B. Please refer to GSA for full details and the most current revision.
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