ISO 6621-3:2000 (R2011)

This part of ISO 6621 classifies materials intended for the manufacture of piston rings, based on their mechanical properties and the stresses the materials are capable of withstanding. This part of ISO 6621 is applicable to piston rings for reciprocating internal combustion engines up to and including those of 200 mm in diameter. It is also applicable to piston rings of compressors working under similar conditions.