TS ISO 6621-1

TS ISO 6621-1 is a vocabulary standard that compiles the most commonly used terms and definitions for piston rings used in internal combustion engines. It provides a common technical language for naming piston ring types as well as selected piston-ring characteristics and phenomena.

Core concepts in piston ring terminology

Piston rings contribute to sealing between the piston and cylinder wall, oil control, and heat transfer. Their geometry, working behaviour, and surface-related features are therefore important to engine performance and durability. By defining the basic terms used in these areas, the standard helps align terminology across manufacturers, designers, test laboratories, and technical documentation.

Scope boundaries and intended use

• The definitions apply to piston rings for reciprocating internal combustion engines.
• They may also be used for piston rings in compressors operating under analogous conditions.
• Further terms and definitions covering measuring principles are given in ISO 6621-2.
• The document also provides equivalent terms in several languages, supporting consistent technical translation.

In practice, TS ISO 6621-1 serves as a reference point for clear and consistent naming of piston-ring concepts. That is especially valuable where small differences in ring type, operating behaviour, or measurement-related terminology can affect understanding and communication.