TS 88-40 ISO 128-40

TS 88-40 ISO 128-40 defines the basic visual conventions for presenting cuts and sections in technical drawings. It standardises how sectional representation is communicated in engineering graphics so that internal form, voids, and changes in shape can be read clearly and consistently.

What sections do in technical drawing

A section is a way of showing a part or structure as if it has been cut by an imaginary plane, making internal details easier to understand. In general technical drawing practice, sections are used to reduce hidden-line clutter, reveal internal geometry, and improve clarity across different engineering disciplines. The subject of this standard is the general presentation of sections, not design rules for the part itself or dimensional requirements.

Scope boundaries and related standards

• The standard applies to technical drawings that follow the orthographic projection methods specified in ISO 5456-2.
• It is relevant to drawings used in mechanical, electrical, architectural, and civil engineering contexts.
• It addresses the general principles for presenting cuts and sections; other drawing, lettering, line, and symbol rules are covered by related ISO 128 and associated standards.
• It forms part of the broader ISO 128 framework for consistent graphic communication in technical drawing.

Consistent sectional presentation supports unambiguous reading in production, inspection, and documentation workflows. For complex parts with cavities, layered features, or dense internal detail, sections are one of the main tools that make technical communication faster and more reliable.

Although this TSE edition has been withdrawn, it remains useful for understanding the conventional language and graphic approach used to interpret and present sections in technical drawing.