NEN ISO 6621-5 : 2005

Defines those quality aspects that are capable of definition but not normally found on a drawing specification. It covers the following: - single-piece piston rings of grey cast iron or steel; - multi-piece piston rings (oil control rings) consisting of cast iron parts and spring components; - single-piece and multi-piece oil control rings of steel, i.e. oil control rings in the form of strip steel components or steel segments (rails) with spring expander components.