ISO 6621‑3 is part three of the multi-series standard that classifies materials intended for the manufacture of piston rings, based on their mechanical properties and the stresses the materials are capable of withstanding.
ISO 6621‑3 is applicable to piston rings for reciprocating internal combustion engines up to and including those of 200 mm in diameter. ISO 6621‑3 is also applicable to piston rings of compressors working under similar conditions.
ISO 6621‑3 on material specifications internal combustion engines — piston rings is useful for:
Many materials are available, made by different manufacturers using different casting and machining techniques, with each suited to a particular application. In many instances, their chemical compositions differ, but the method of manufacture and the heat treatment, if any, result in materials from different manufacturers with similar mechanical properties. The performance of rings made from two different materials might be very similar, i.e., several subclasses of materials could meet a given requirement.
ISO 6621‑3 provides a user guide to the types of materials available and material specifications for piston rings that you can you to manufacturers good quality piston rings.
ISO 6621‑3 gives the specifications for stresses the materials are capable of withstanding. This will help you increase the durability of the piston rings.
BS ISO 6621‑3:2021 is the third edition that cancels and replaces the second edition (ISO 6621‑3:2000), which has been technically revised.
The main changes compared to the previous edition are as follows:
ISO 6621-3:2021