I can't find the SmartMates icon in SolidWorks 2004 or later
One of the enhancements in SolidWorks 2004 to improve ease-of-use for assembly mating was to allow SmartMates to be applied by simply holding down the Alt key during a drag and drop operation, to snap parts together. Because of this new ability, the SmartMates icon was removed from the assembly toolbar.
However, if you prefer the older method of adding SmartMates, you can still access that older icon from within the Move Component command. Go to Tools - Component - Move, or hit the Move Component icon on the assembly toolbar. Then, at the top of the PropertyManager you will see the SmartMates icon, which looks like this:
Click this icon to turn on SmartMates. You can now add mates to SolidWorks components by double-clicking on the first face or edge to be mated, and then single-clicking on a second face or edge to mate to. A pop-up box will then appear to confirm the mate type and alignment. Click OK (green checkmark) to apply the mate. Repeat as needed.
