FreeCAD Body vs Part vs Component: Understanding the Difference

When you start working with FreeCAD, you’ll quickly encounter terms like Body, Part, and Component. These terms can be confusing because they all appear in workflows involving 3D models and assemblies—but they serve very different purposes.

Understanding how these objects work is important if you want to create clean, editable, and well-organized FreeCAD projects.

Quick Reference: Body vs Part vs Component

1. What Is a Body in FreeCAD?

A Body is primarily used for creating a single contiguous solid using the Part Design workflow. Think of a Body as a container for the features that build one mechanical component.

For example, a mounting bracket contains sequential modeling operations:

When Should You Use a Body?

• Creating a single mechanical part
• Working primarily with the Part Design Workbench
• Building a parametric model
• Creating features such as Pad, Pocket, Fillet, and Chamfer
• Maintaining an organized feature history

2. What Is a Part in FreeCAD?

A Part container is used to organize multiple objects into a logical group without forcing them to become a single contiguous solid.

Part Workbench vs. Part Container

• Part Workbench: A modeling environment with tools for CSG modeling, primitives, Boolean operations, extrusions, and geometric transformations.
• Part Container: An organizational object in the tree hierarchy to group related items (Shaft, Gear, Bearing, Housing).

Can a Part Contain Multiple Bodies?

Yes. This is ideal for multi-body mechanisms:

3. What Is a Component in FreeCAD?

A Component is an assembly-level concept rather than a single specific FreeCAD modeling feature. In an assembly, a component represents an individual item participating in the overall structure.

When Should You Use Each One?

Common Beginner Mistakes to Avoid

1. Treating Body and Part as Interchangeable: A Body is feature-based parametric solid modeling; a Part is primarily an organizational/CSG container.
2. Putting Everything Into One Body: Combining separate components into one Body breaks downstream assembly workflows and complicates editing.
3. Confusing Part Container with Part Workbench: Understand the difference between the organizational object and the toolset.
4. Assuming Component Is a Static Tool: Component terminology depends on the assembly workbench used (Assembly3, Assembly4, A2plus, etc.).
5. Ignoring Model Organization: Large projects quickly break without structured hierarchies.

Recommended FreeCAD Workflow

1. Step 1: Create a Body for each independent parametric part.
2. Step 2: Build each part sequentially using sketches and Part Design features.
3. Step 3: Organize related objects using Part containers.
4. Step 4: Transition to an assembly workbench once individual parts are complete.
5. Step 5: Treat each manufactured item as an assembly Component.