ASTM D1418 is commonly used to designate the correct polymer to be used in rubber compounds listed on material specification or part drawings.
The below table is a list of commonly used rubber polymers used in the sealing industry. This is not a complete list: more options can be found in the standard.
List of Rubber per ASTM D1418
The rubber is classified and coded based on the chemical composition of the polymer chain of the rubber polymer. As we know from our post on rubber compounds, this is the main ingredient of a rubber compound — but not the only ingredient. It is not like plastic where it is a single ingredient composition (for example, 100% Nylon plastic).
Rubber needs to be formulated with different ingredients to give its physical properties and processing characteristics. This means that just listing these nomenclatures should not consider this is the formulation. Compound numbers or ASTM D2000 specification should also be used in writing a specification to give desired physical property requirements.