From FreeCAD Documentation
- Optionally select one object. The object must lie on the current Draft working plane.
- There are several ways to invoke the command:
- Press the Offset button.
- Select the Modification → Offset option from the menu.
- Use the keyboard shortcut: O then S.
- If you have not yet selected an object: select an object in the 3D view.
- The Offset task panel opens. See Options for more information.
- To define the offset distance do one of the following:
- Pick a point in the 3D view.
- Enter a numerical value:
- Make sure the pointer is on the correct side of the object in the 3D view.
- Do not move the pointer out of the 3D view.
- Enter a Distance.
- Press Enter to finish the command.