3/16" Thick, Round Cross Section, Shore 65 - 75, -65 to 300°F EPDM (Ethylene Propylene) is ideal for phosphate ester based hydraulic fluids. It provides resistance to weather, abrasion, hot water, steam, silicone fluids, dilute acids and dilute ketones. It is not resistant to petroleum fluids and diester lubricants.|Round cross-section shapes can be used in both static and dynamic applications. They are used as a mechanical seal or gasket and are seated in a groove and compressed during assembly between two or more parts.