TS ISO 7904-1

TS ISO 7904-1 is a symbol standard for plain bearings that defines the basic symbols used in this field and explains how those symbols may be supplemented by subscripts and superscripts. It provides a common technical language for drawings, calculations, catalogues, and data exchange where consistent notation matters.

Why a symbol system matters in plain-bearing engineering

Plain bearings are machine elements that support relative motion between surfaces while controlling friction. In this area, symbols are used to represent quantities such as load, speed, friction, clearance, and related technical concepts in a compact and standardised way. That makes it easier for designers, manufacturers, and users to interpret the same notation across different documents and contexts.

The scope of this part includes both the basic symbols and the additional signs used as subscripts or superscripts. This distinction is important: the base symbol identifies the physical quantity, while the added index or sign can identify the axis, position, direction, or other qualifying detail associated with that quantity.

What this part covers in practice

• Definition of the basic symbols
• Specification of additional signs used as subscripts and superscripts
• A shared reference for consistent notation in plain-bearing terminology
• Notation rules, rather than numerical design values or performance limits

This record is based on ISO 7904-1 and is now withdrawn. Even so, the subject remains useful in plain-bearing engineering because standardised notation reduces ambiguity in technical communication and, together with the related Part 2, supports a more complete symbol system.