Aug, 26 2019

Flex Fatigue Resistant Silicones: AA 59588 Class 3A and 3B Qualified



Flex Fatigue Resistant Silicones: AA 59588 Class 3A and 3B Qualified

Specialty Silicone Products (SSP) supplies flex fatigue resistant silicones that are fully tested to AA 59588 Classes 3A and 3B from the U.S. General Services Administration (GSA). AA 59588, an aerospace and military standard, supercedes ZZ-R-765 and contains six alphanumeric classes. Each AA 59588 class describes material properties, but only Classes 3A and 3B include requirements for flex fatigue resistance – a measure of an elastomer’s ability to withstand repeated flexing and bending.

Other suppliers may claim that their silicones meet the AA 59588 specification, but SSP is one of very few companies that qualifies elastomers to this GSA standard with no exceptions for flexural testing. That’s why many engineers and buyers in the aerospace and defense industries see SSP as the technical experts for AA 59588 Class 3A and 3B materials. Applications for silicones that need high flex-fatigue resistance include door seals, window seals, and the vibration-isolating mounts used with compressors and alternators. 

AA 59588 Class 3A and 3B Silicones

In a 2016 white paper, SSP described how the Akron Rubber Development Laboratory (ARDL) tested samples of SSP-200T, a 50-durometer silicone, according to ASTM D813 – 07(2014). This standard ASTM test includes the DeMattia Flex Resistance test, a dynamic protocol that measures crack growth over thousands of cycles. As the data sheet for SSP-200-T shows, this silicone’s flex resistance (140,000 cycles) meets AA 59588, Class 3B, Grade 50 requirements and has typical values of 0.42-in. with 0.5-in. maximum.

Since 2016, SSP has qualified numerous AA 59588 3A and 3B materials in various grades or durometers. Today, SSP can supply you with silicones that meet the full requirements of these classes and grades. The table below describes our current product offerings. Choose the appropriate links to see the data sheets.

Class

Grade

SSP Material

Class 3A

Grade 50

SSP-2523-T

Class 3A

Grade 60

SSP-2524-T

Class 3B

Grade 50

SSP-200-T

Class 3B

Grade 60

SSP-392-T

Class 3B

Grade 70

SSP-2521-T

SSP-392-T also has a certificate of analysis that you can view on-line.

Military and Aerospace Silicones

Specialty Silicone Products (SSP) offer a wide range of military and aerospace silicones, including fluorosilicones that are fully certified to MIL-DTL-25988. This U.S. military specification covers sheets, strips, molded parts and extruded shapes that require resistance to oils and fuels.  SSP also offer silicones that meet aerospace material specifications (AMS) such as AMS 3301, AMS 3302, and AMS 3303.

For more information, email Dominic Testo or contact SSP on-line.