Choosing the right CAD format is critical for clear communication and error-free manufacturing. When you export and send files, the format you select determines what the recipient can see, measure, and edit. This guide helps you select the best file type for your specific need.
Which Format to Use: A Quick Guide
To send a 3D model to any manufacturer...
- Format: STEP (.step, .stp)
- Purpose: The universal standard for 3D solid models.
To send a 2D profile for laser or waterjet cutting...
- Format: DXF (.dxf)
- Purpose: The industry standard for 2D vector geometry that machines can read.
To send a 2D drawing for viewing or quoting...
- Format: PDF (.pdf)
- Purpose: Anyone can open it. Best for dimensions, notes, and markups.
To send a model for 3D printing...
- Formats: 3MF (.3mf) or STL (.stl)
- Purpose: 3MF is modern and includes units/color. STL is a basic but widely supported mesh.
To collaborate with someone using the same CAD software...
- Format: Native Files (.sldprt, .f3d, etc.)
- Purpose: Preserves the complete feature history for direct editing.
To share a lightweight 3D preview...
- Formats: JT (.jt) or 3D PDF
- Purpose: Small files for quick visualization without special CAD software.
Key Format Details
- STEP (.step, .stp): The most important format for interoperability. It provides a robust 3D model (a "dumb solid") that preserves geometry without revealing your proprietary design history. It's the safest and most reliable choice for sharing 3D designs externally.
- 3MF (.3mf) vs. STL (.stl): Both are for 3D printing, but 3MF is superior as it bundles units, color, and material data into a single file, preventing common scaling and configuration errors. Use STL only when 3MF is not supported.
- PDF vs. DXF: Use PDF for 2D drawings that need to be viewed, printed, or marked up by people. Use DXF when a machine needs to read the 2D geometry for cutting operations.
- Native Files: Only share native files (e.g., from SolidWorks, Inventor, Creo) when your collaborator uses the same software and needs to modify the original parametric design. For external partners, always prefer sending a STEP file.
Pre-Flight Checklist
Before you send any file, confirm the following:
- Package Assemblies: Send all assembly parts in a single zipped folder or a packaged file.
- Include a Fallback: When sending native files, always include a STEP version as well.
- Communicate Clearly: State the file's units (e.g., mm or inches) and original software version.
- Provide a BOM: If it's an assembly, include a Bill of Materials.
- Protect IP: Sending a STEP file is the standard way to protect your intellectual property, as it removes the editable feature history.
Simplify Your CAD Collaboration
Manually exporting files and managing feedback over email can lead to confusion, version control issues, and costly mistakes. Instead of juggling different formats, a dedicated platform can streamline your entire design review process.
CoLab is built to handle this complexity, eliminating issues with version control and feedback by allowing teams to review and mark up designs in a central location. It automatically supports a wide range of native and neutral file formats, simplifying collaboration for your entire team.
