Technical Drawings: Types, Classification, and Purpose

Classification of Technical Drawings

Technical drawings, as defined by standards like UNE 1 to 166 - 1:1996, ISO 10209 - 1:92, or DIN 199, are classified into different types based on their representation, form, content, and purpose.

Technical Drawings by Representation

• Sketch: Freehand representations used for initial product development.
• Scale Drawing: Accurate representations drawn to scale, including all necessary technical details.

Technical Drawings by Form

• Original Drawing: The initial drawing, created manually or using CAD software, typically on transparent paper.
• Reproduction: A copy of the original drawing, produced through printing, photography, or blueprinting.

Technical Drawings by Content

• Assembly Drawing: A comprehensive drawing showing a mechanism, facility, machinery, or construction with all its elements and operating conditions.
• Assembly Illustration: A representation showing how groups or parts are assembled, including necessary dimensions and details.
• Group Drawing: A drawing illustrating the mounting position of a group of elements within a manufacturing unit.
• Exploded View: A drawing that represents a single piece with all necessary information, including shapes, sizes, and notations for complete definition and fabrication.

Technical Drawings by Purpose

• Project Drawing: A drawing that focuses on the arrangement of elements within a project, without including all technical data required for manufacturing.
• Manufacturing Drawing: A drawing containing all the technical data necessary for manufacturing a product.
• Blank Drawing: A drawing representing a part as it is obtained from forging or casting before machining.
• Roughing Drawing: A drawing showing the intermediate stage of manufacturing an item.
• Supplementary Drawing: An additional drawing that supplements an existing drawing, often to save space or represent repeated elements.
• Offer Illustration: A drawing used to accompany a budget, contract, or order request.
• Outline: Simplified representations using standardized symbols to show the mounting or attachment of components or parts.

Drawings can also be categorized as:

• General Plan or Joint Plan
• Manufacturing and Disassembly Plan
• Assembly Plan
• Outlook Rush Plan