SAE J 200 Codes AA, BA
Relative Cost Low
Hydraulic brake systems seals and diaphragms
Performs Well in…
Silicone oil and grease
Non-mineral oil based brake fluid
Doesn’t Perform Well in…
Petroleum oils and fuels
Aromatic, aliphatic, or halogenated hydrocarbons
SBR is a copolymer of styrene and butadiene. Compound properties are similar to those of natural rubber. It is also known as Buna S, or GR-S (Government RubberStyrene). SBR was first produced under government control between 1930 and 1950 as a replacement for natural rubber.
The main use for styrene butadiene today is in the manufacture of automobile tires. O-ring usage has been on decline since the introduction of ethylene propylene (EPDM). SBR is mostly used in seals for non-mineral oil based brake fluid applications.
Good resistance to brake fluids
Good resistance to water
Poor petroleum oil and solvent resistance
Poor weather resistance
Seldom used in modern sealing applications