Translations:Export to STL or OBJ/2/en

From FreeCAD Documentation

In this tutorial we will cover how to export STL/OBJ-files from FreeCAD. The mesh-format STL/OBJ is dimensionless; FreeCAD will assume on export that the units used in the model are in mm. If this is not the case you have to scale your model. One way to do this is using Draft Scale.