Putting Things in Place with Assemblies - Inventor 2013 and Inventor LT 2013 Essentials - page 100

The Mate Constraint
This tool has two primary options: a Mate solution and a Flush solution. Each will
reposition components based on the selected geometry with the ability to apply an
Offset value in the dialog box that will create a gap or an interference between the
component depending on whether the value is positive or negative and how the
parts are aligned.
The Mate solution works on planes, axes, and points, and it behaves as though it
puts these entities in opposition to one another. If you put a box on top of another
box in the real world, you could say that the top of the lower box was pushing against
the bottom of the upper one. In Inventor, this would be a Mate/Mate constraint.
First you will use the Mate solution in your assembly:
1. Make certain that the 2013 Essentials project file is active and then
open c04-01.iam from the Assemblies\Chapter​4 folder.
2. Launch the Constrain tool from the Position panel or from the mark-
ing menu.
3. Set Constraint Type to Mate, and leave Solution at its default (Mate).
4. In the Selection group, the button for 1 will be depressed. Click the
blue face on the red part for the first selection.
5. Once the first object is clicked, the second one will be enabled. Click
the blue face on the purple part.
The two parts automatically snap together (see Figure 4.3). You
can turn this off by deselecting the Preview icon in the dialog box.
FIGURE 4.3 The components move into position as you apply
constraints.