TS EN ISO 12181-2

TS EN ISO 12181-2 is the Turkish edition of the standard on specification operators for roundness within the Geometrical Product Specifications (GPS) system. This part addresses how a complete roundness specification is formed for integral features and how roundness profiles are expressed for circular-type features. In general technical terms, roundness is the departure of a real circular profile from an ideal circle, so it is central to drawing interpretation, measurement evaluation, and functional acceptance of round features.

Roundness specification and integral features

The specific subject of this standard is the complete specification operator for roundness of integral features only. In GPS terminology, a specification operator is the structured way a geometric requirement is defined, interpreted, and evaluated. The key distinction here is that roundness is not treated as a vague shape idea, but as a geometric characteristic of a defined circular feature that can be specified consistently. That makes the relationship between design intent, measurement result, and technical communication much clearer.

Where the concept is used

Roundness matters in many precision components, especially shafts, bores, and other circular sections where geometric deviation can affect fit, rotation, sealing, or contact behavior. The standard focuses on complete roundness profiles, which supports consistent notation and interpretation in the GPS framework. It is therefore useful wherever circular features must be described and assessed in a way that aligns technical drawings with metrology practice.

• Applies to the roundness specification of integral features only.
• Covers complete roundness profiles for circular-type features.
• Supports consistent GPS-based interpretation of circular geometry.
• Helps align design notation with measurement and evaluation practice.