Use the Constraint menu to apply a constraint that does the following:
Parallel Face. Positions a movable part instance so that a selected face is parallel to a selected face of a fixed part instance.
Face to Face. Positions a movable part instance so that a selected face is parallel to and a specified distance away from a selected face of a fixed part instance.
Parallel Edge. Positions a movable part instance so that a selected edge is parallel to a selected edge of a fixed part instance.
Edge to Edge. Positions a movable part instance so that a selected edge is parallel to and a specified distance away from a selected edge of a fixed part instance.
Coaxial. Positions a movable part instance so that the axis of revolution of a selected face is coincident with the axis of revolution of a selected face of a fixed part instance.
Coincident Point. Positions a movable part instance so that a selected point is coincident with a selected point of a fixed part instance.
Parallel CSYS. Positions a movable part instance so that a selected datum coordinate system associated with the instance is parallel to a selected datum system of a fixed part instance.
You may find it more convenient to access the constraint tools using the Assembly module toolbox. For a diagram of the tools in the Assembly toolbox, see Using the Assembly module toolbox, Section 13.8.