TS ISO 4378-2

TS ISO 4378-2 is a terminology standard for plain bearings, focused on the most commonly used terms for friction and wear together with their definitions and classification. Plain bearings are machine elements that support rotational or reciprocating motion through sliding contact, where the interacting surfaces move relative to one another in a controlled way. This part helps align the language used to describe the tribological behaviour of those bearings.

How friction and wear relate to plain bearing behaviour

Friction is the resistance that arises when surfaces move relative to each other; wear is the gradual loss of material from those surfaces due to that contact and motion. In plain bearing applications, the two are closely connected because bearing performance depends not only on load-carrying ability, but also on how the surface pair interacts, the lubrication conditions, and the operating regime. In general technical use, shared terminology matters because it keeps design, testing, maintenance, and failure analysis focused on the same concepts.

What this part organises in the vocabulary

The document defines the most frequently used terms related to friction and wear and classifies them. It also gives short forms for some terms and word combinations, where those abbreviations can be used without ambiguity. That makes technical writing more compact while preserving meaning in engineering documents, catalogues, and communication. The standard is centred on tribological terminology for plain bearings and supports a common language for surface interaction, material choice, and service behaviour.

• Standardises the meaning of key terms and reduces interpretive variation.
• Treats friction and wear together in the plain bearing context.
• Provides short forms only when they are unambiguous.
• Uses classification to group related concepts in a structured way.