TS EN ISO 12780-1

TS EN ISO 12780-1 addresses the terms, concepts, and straightness parameters used within geometrical product specifications (GPS). This part establishes a common technical language for the straightness of individual integral features and focuses on complete straightness profiles, helping users interpret how straightness is described and referenced in specification and measurement contexts.

Straightness in the GPS framework

Straightness is a fundamental geometric characteristic describing how closely a line element or a feature intended to be linear follows an ideal straight line. In GPS practice, such terminology is standardized so that drawings, inspection results, and verification methods can be understood consistently. The subject of this standard is the vocabulary and parameterisation of straightness; it does not, from the provided scope, set a specific tolerance value, a universal acceptance limit, or a single mandatory test method.

What this part contributes technically

• terminology for straightness of individual integral features
• parameters used to express straightness
• conceptual treatment of complete straightness profiles
• a shared basis for specification and verification

In general engineering use, straightness matters for shafts, edges, guide surfaces, and other linear features where small deviations can affect fit, alignment, motion, or measurement reliability. Vocabulary standards like this one are especially useful because they separate the idea of the geometric characteristic from the way it is measured or controlled in a particular application. TS EN ISO 12780-1 therefore serves as a reference for understanding straightness terminology within the broader GPS system, rather than as a standalone manufacturing rule.