CAD Standards, GD&T & Engineering Conventions brings together the rules that make technical information consistent and understandable. It covers ISO, ASME, ANSI and industry standards, geometric dimensioning and tolerancing, fits, surface texture, layer systems, drawing conventions and open data standards for BIM, GIS and electronics.
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Use this section as a reference when creating company standards, reviewing drawings or applying tolerancing requirements.
International Standards
Key topics include ISO Technical Product Documentation, ISO GPS Standards, ISO 1101, ISO 5457, ISO 5455, and ISO 128. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: ISO Technical Product Documentation, ISO GPS Standards, ISO 1101, ISO 5457, ISO 5455, ISO 128, ISO 129, ISO 13567.
North American Standards
Key topics include ASME Y14 Standards, ASME Y14.5, ASME Y14.41, ANSI Drawing Standards, United States National CAD Standard, and AIA CAD Layer Guidelines. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: ASME Y14 Standards, ASME Y14.5, ASME Y14.41, ANSI Drawing Standards, United States National CAD Standard, AIA CAD Layer Guidelines, Canadian CAD Standards.
GD&T Fundamentals
Key topics include Datums, Datum Reference Frames, Basic Dimensions, Feature Control Frames, Material Condition Modifiers, and Virtual Condition. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: Datums, Datum Reference Frames, Basic Dimensions, Feature Control Frames, Material Condition Modifiers, Virtual Condition, Bonus Tolerance, Composite Tolerancing.
GD&T Controls
Key topics include Straightness, Flatness, Circularity, Cylindricity, Parallelism, and Perpendicularity. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: Straightness, Flatness, Circularity, Cylindricity, Parallelism, Perpendicularity, Angularity, Position.
Fits, Limits and Tolerances
Key topics include Nominal Size, Basic Size, Upper and Lower Limits, Allowance, Clearance Fits, and Transition Fits. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: Nominal Size, Basic Size, Upper and Lower Limits, Allowance, Clearance Fits, Transition Fits, Interference Fits, Hole-Basis Systems.
Surface Texture and Manufacturing Symbols
Key topics include Surface Roughness, Surface Finish Symbols, Machining Allowances, Lay Direction, Welding Symbols, and Brazing Symbols. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: Surface Roughness, Surface Finish Symbols, Machining Allowances, Lay Direction, Welding Symbols, Brazing Symbols, Casting Symbols, Inspection Symbols.
CAD Layer Standards
Key topics include Layer Naming, Layer Colors, Layer Line Types, Discipline Codes, Status Codes, and Phase Codes. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: Layer Naming, Layer Colors, Layer Line Types, Discipline Codes, Status Codes, Phase Codes, ISO 13567, AIA Layer Guidelines.
Drawing and Model Standards
Key topics include File Naming, Drawing Numbering, Sheet Numbering, Revision Standards, Title Block Standards, and Model Naming. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: File Naming, Drawing Numbering, Sheet Numbering, Revision Standards, Title Block Standards, Model Naming, Component Naming, Coordinate Standards.
BIM and Open Data Standards
Key topics include IFC, BCF, IDS, bSDD, COBie, and openCDE. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: IFC, BCF, IDS, bSDD, COBie, openCDE, Model View Definitions, Exchange Information Requirements.
GIS and ECAD Standards
Key topics include OGC Standards, CityGML, 3D Tiles, LandXML, IPC Standards, and Gerber Standards. Additional entries will expand the subject with definitions, methods, examples and related standards.
Representative topics: OGC Standards, CityGML, 3D Tiles, LandXML, IPC Standards, Gerber Standards, IPC-2581, STEP AP242.
How CADpedia Organizes This Knowledge
Each topic is developed as a separate encyclopedic entry. Definitions explain the terminology, reference pages document standards and formats, software profiles describe platforms, and practical entries connect the concepts to professional workflows. Related pages are linked across categories so readers can move from theory to software, standards, files and industry applications without repeating the same information.