PartDesign Line

From FreeCAD Documentation

PartDesign Line

Menu location
Part Design → Create a datum → Create a datum line
Default shortcut
Introduced in version
See also
PartDesign Point, PartDesign Plane


Creates a datum line which can be used as reference for sketches, other datum geometry or features. For example it can be used as revolution axis for Revolution and Groove features.

Two Datum lines through opposite corners of the cube meet at the center of mass.


  1. Press the Create a datum line button.
  2. Define Line parameters. Select a first reference in the 3D view to filter the available attachment modes.
  3. Depending on the selected reference, there may be one or more attachment modes available in the the list. The most likely one will automatically be selected and shown in bold in the list. The text Attached with mode along with the attachment mode name will appear in green at the top of the Parameters panel.
  4. To add an additional reference, press the next Reference button. Once pressed its label changes to Selecting... until a selection is made.
  5. Select an attachment mode in the list.
  6. Define Attachment Offset values.
  7. Press OK.


Double-click the DatumLine label in the Model tree or right-click and select Edit datum in the contextual menu to edit its parameters. For more details about Attachment mode and Attachment offset, see Part EditAttachment.


  • DataMapMode: lists the attachment mode used.
  • DataAttachment Offset: applies a transformation (translation and rotation) in reference to the attachment placement.
  • DataLabel: name given to the object, this name can be changed at convenience.