TS 5620

TS 5620 addresses the rules for item numbering in assembly technical drawings. In engineering documentation, clear and consistent identification of each component in an assembly is essential for reading the drawing, linking it to a parts list, and keeping documentation organized. This standard focuses on that numbering approach for component parts shown in assembled views.

How item references work in assembly drawings

In general technical practice, an item reference assigns a unique identifier to each component in an assembly. The reference is typically shown with a balloon, leader line, or similar callout and is matched to a parts list, bill of materials, or assembly instruction. This creates a practical connection between the visual drawing and the structured product data, making it easier to identify parts, quantities, and relationships within the assembly.

What this standard covers and what it does not

According to the supplied scope, this standard covers the rules for item references of component parts in technical drawings. Its focus is the organization of part numbering within an assembly drawing, not general drawing methods, dimensional rules, or manufacturing tolerances. In other words, it deals with how components are referenced so the assembly documentation remains consistent and readable.

• Identifying components within an assembly
• Presenting item references in a consistent drawing format
• Supporting the link between drawing and parts list
• Keeping repeated components referenced in a uniform way

TS 5620 is presented as the Turkish equivalent of ISO 6433:1981. For technical drawing workflows, a shared item-reference convention helps different teams interpret assembly documentation in the same way, especially where a single drawing must support design, parts management, and production communication.