This document provides a method/procedure for specifying the properties of vulcanized elastomeric materials (natural rubber or synthetic rubbers, alone or in combination) that are intended for, but not limited to, use in rubber products for automotive applications. This document covers materials that do not contain any re-use; recycled; or regrind materials unless otherwise agreed to by manufacturer and end user. The use of such materials, including maximum % must be specified using a âZâ suffix. This classification system covers thermoset High Consistency Elastomers (HCEâs) only. Thermoplastic Elastomer (TPE) materials are classified using SAE J2558. Silicone Formed In Place Gasket (FIPG) systems such as Room Temperature Vulcanized (RTV) Silicones, and Liquid Silicone Rubber (LSR) systems are classified using ASTM F 2468.