TS EN ISO 12180-1

TS EN ISO 12180-1 is a Geometrical Product Specifications (GPS) standard devoted to the vocabulary and parameters of cylindricity. It establishes the terminology and concepts used to describe cylindrical form for individual complete integral features, giving designers, metrologists and manufacturers a common technical language for the same geometric characteristic.

Why cylindricity is treated as a distinct form characteristic

Cylindricity is more than roundness at one section or a simple size check. In general technical terms, it describes how closely a real surface approaches an ideal cylinder over its full length and around its full circumference. That makes it a form characteristic, closely related to other GPS notions such as roundness, straightness, axis-related concepts and surface form, but not interchangeable with them. The role of this part is to organize the language around that distinction.

What this part covers conceptually

• Terms and definitions related to cylindricity
• Concepts used to describe cylindrical form
• Vocabulary for individual complete integral features
• Common interpretation of cylindricity parameters within the GPS framework

Rather than prescribing a test procedure or numeric acceptance limits, the standard focuses on terminology and conceptual structure. That makes it useful wherever cylindrical features must be specified, inspected or reported consistently, including technical drawings, measurement documentation and general metrology practice. The broader value of such vocabulary standards is clarity: everyone involved can discuss the same geometric condition without ambiguity.

As Part 1 of the series, this document provides the conceptual foundation for the subject of cylindricity. It is best understood as the terminology base for the wider ISO 12180 family and for related GPS standards that address form specification and verification.