TS EN ISO 1101

TS EN ISO 1101 is a geometrical product specifications (GPS) standard that deals with how tolerances of form, orientation, location and run-out are expressed. In technical drawings and product definition, the key objective is to define not only size, but also the shape accuracy and geometric relationships that affect how a part functions. This standard helps establish a consistent language for geometric deviations that matter in design, manufacture and inspection.

The technical role of geometric tolerancing

In general technical terms, form tolerances control how far a surface or axis may deviate from its intended geometry, orientation tolerances define how a feature is aligned relative to reference datums, and location tolerances govern the position of features with respect to one another or to datums. Run-out tolerances limit the variation observed on rotating parts as a surface turns about an axis. These categories separate different kinds of error, which is important for both measurability and function.

What this standard covers

From its title, the scope of the standard is the definition of geometrical tolerances in the categories of form, orientation, location and run-out. Within the GPS framework, the standard standardises the interpretation of symbols and tolerance frames so that design, manufacturing and inspection can rely on a common language. It is therefore a core technical reference for understanding how geometric features are specified and read across disciplines.

• Form tolerances address the intrinsic accuracy of geometry; orientation and location tolerances relate a feature to a datum system.
• Run-out tolerances are especially relevant for rotating or rotation-related parts.
• Within GPS, the standard helps make geometric quality explicit and unambiguous in technical product definition.