TS ISO 8015

TS ISO 8015 is a standard on the fundamental principle of tolerancing in technical drawings, defining the relationship between dimensional tolerances and form-and-position tolerances. In general technical terms, this distinction matters because a part may be acceptable in size yet still be unacceptable in geometry; the standard addresses the rules governing that relationship, so drawings are interpreted consistently.

Dimensional tolerance versus geometric tolerance

Dimensional tolerances set the permissible limits of a size. Form and position tolerances, by contrast, control geometric characteristics such as straightness, flatness, roundness, parallelism, perpendicularity, position, and runout. In normal engineering practice, these two families of tolerances serve different purposes: one limits variation in size, while the other limits variation in shape or location. This standard focuses on the governing principle that connects them.

Why this principle matters in drawings

A fundamental tolerancing standard like this helps engineers, inspectors, and manufacturers read technical drawings with the same expectations. It supports clearer communication between design intent and inspection practice, especially where a feature’s size alone does not guarantee its functional geometry. TS ISO 8015 provides the general framework for interpreting tolerances; detailed geometric symbols, datums, and specific application rules are handled in the wider technical drawing system.

• Explains the relationship between dimensional tolerances and geometric tolerances in technical drawing.
• Provides a basic interpretive framework for form and position tolerances.
• Helps distinguish size control from geometric control on the same drawing.
• Supports a common interpretation language for drawing, manufacturing, and inspection.