TS EN ISO 128-2

TS EN ISO 128-2 sets out the basic conventions for the types, designation and configuration of lines used in technical product documentation. In technical drawings, diagrams, plans and maps, lines do more than outline shapes: they distinguish visible edges, hidden details, axes, dimension-related information and directional references. This standard provides the common graphical framework that makes that visual language consistent and readable across documents.

Line types and their role in technical communication

In general technical practice, line thickness, continuity, breaks and end forms all affect meaning. Continuous lines are commonly used for prominent edges, while dashed or dotted patterns help separate hidden or auxiliary information. This part addresses how line categories are defined and applied consistently within technical documents, helping the same product, assembly or structural element appear with the same notation logic across different drawings. That consistency is essential when several disciplines work from the same documentation set.

Leader lines, reference lines and note placement

The standard also gives general rules for leader lines and reference lines, including their components and the arrangement of instructions placed on or alongside them. This supports clear placement of dimensions, symbols, callouts and explanatory text without cluttering the drawing. Annexes provide additional information for mechanical, construction and shipbuilding technical drawings. Overall, the document helps harmonise line usage across sectors and serves as a core reference for understanding the graphical conventions used in the full product documentation package for a product, subassembly or assembly.