You can add mates to constrain assembly components relative to each other.
Note:
The currently active product might contain solid bodies as well as components.
Mates can be applied between components.
Mates cannot be applied between solid bodies.
In the 3D area, Ctrl + select a reference such as a face or edge from each of the components to mate.
The context toolbar appears. The toolbar contains buttons for all mate commands that are valid for the two selected references.
To preview potential mates, hover the mouse pointer over each button.
Mate types that have two possible alignments have two buttons so you can preview both alignments. For example, a coincident mate has two possible alignments.