On the command bar, in the Relationship Types list, click the Center-Plane button.
On the command bar, specify Single or Double. Double will find the center between selected geometry on the part that will be positioned.
Select the geometry to be centered.
Select the geometry that defines the center plane.
Click OK.
Tip:
The relationship centers a selected key-point, planar face, plane, edge, cylinder axis, edge or plane/face pair onto the symmetry plane defined between two planar faces, reference planes or two key-points.
The command will also center objects between faces and planes that are not parallel.
The relationship can be applied between 2 and a maximum of 4 components.