Anyone who drafts in FreeCAD knows that drawing a bolt, a pipe, or a standard part from scratch takes time without adding value to the design. That is why the FreeCAD community has assembled ready-made libraries: a general parts library, and tools that generate bolts and standard profiles. But note: these sources do not use a single license, and each has its own terms, which is what this article explains.
| Source | What it is | License |
|---|---|---|
| FreeCAD-library | Ready-made parts library (model files) with a macro for browsing it | Parts: CC BY 3.0, and each part’s author must be credited. Macro and code: LGPL 2.1 or later |
| Fasteners Workbench | A software add-on inside FreeCAD that generates bolts and nuts | GPL 2.0 or later (for the software) |
| BOLTS | Parametric standard parts library (data and code that generate parts) | LGPL 2.1 or later, and the repository is now archived |
Licenses are taken from the license files and add-on data (package.xml) in each repository, as of 9 November 2026.
1. FreeCAD-library parts library
A GitHub repository maintained by the FreeCAD user community, not an official part of the FreeCAD project itself. It contains a large number of parts, organized into folders by category:
- Architectural Parts: ready-to-insert architectural elements, including tree models for site layouts.
- HVAC and Pipes and tubes and Hydraulics: air-conditioning, piping, and pump parts.
- Mechanical Parts and Electrical Parts and Electronics Parts: mechanical and electrical parts.
- And other folders such as Logistics (platforms and shipping containers), Topography, and Symbols.
Formats
Each part comes in FreeCAD’s native FCStd format, and usually also includes a STEP file that can be opened in most other CAD programs (SolidWorks, Fusion, Inventor). Some also include STL for preview or 3D printing.
How to use it
- In FreeCAD, open Tools → Addon Manager, search for Parts Library, and install it.
- A window appears where you can browse the library and add the part to your project with two clicks.
- Or download the entire repository from GitHub and open any
FCStdfile, or import theSTEPfile directly.
License: author credit required
The license file in the repository states that all of its contents, every part and every helper file, are licensed under CC BY 3.0, and that the rights to each part belong to its author. In practice:
- You may use, modify, and distribute the part, including commercially.
- You must credit the author of the part. You can find this inside the FCStd file or in the commit history on GitHub.
- The program code in the repository (the PartsLibrary macro and indexing tools) has a separate license: LGPL 2.1 or later.
2. Fasteners Workbench
Not a file library, but a software add-on inside FreeCAD that generates bolts, nuts, and washers according to specifications (ISO, DIN, and others) in the diameter and length you choose, and is installed from the Addon Manager. The add-on itself is licensed under GPL 2.0 or later, as stated in its official data (package.xml) and the license file in its repository.
3. BOLTS
A parametric standard-parts library (bolts, steel profiles, and connectors) that works with FreeCAD and OpenSCAD. It has been relicensed under LGPL 2.1 or later, but its repository is now named BOLTS_archive, meaning it has been archived. So make sure it is compatible with the version of FreeCAD you use before relying on it in a project.
Library license is not the same as tool license
This is where confusion usually happens, so pay attention to the difference between two types of sources:
- A model library such as FreeCAD-library: the file itself (the part) is the licensed work. If you take a part and put it in your project or distribute it, CC BY 3.0 terms apply to it, most importantly attribution to its author.
- A software add-on such as Fasteners: the license (GPL) governs the add-on code itself, meaning copying, modifying, and redistributing it. But the bolt generated by the tool inside your design is part of your work, and the software license does not automatically extend to it in the usual case.
This is general information, not legal advice. If the product is commercially significant or you will distribute the modified add-on itself, read the full license text or consult a specialist.
FreeCAD-library on the official GitHub ↗
Other source links: Fasteners Workbench and BOLTS. We do not host these files. The licenses are quoted from the LICENSE files and add-on data in each repository as of 9 November 2026, and they may change.
Related libraries and tools
- Poly Haven: Free textures, HDRI lighting, and 3D models
- ambientCG: free PBR textures for architectural design
- Engineering unit converter for converting torque, force, and pressure between units.
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