SmartMates Save Time in Assemblies

1 May, 2003 By: Greg Jankowski

When creating an assembly, you need to tell SolidWorks how the assembly components will interact with one another. A mate helps constrain one or more of the six degrees of freedom (up or down, front or back, in or out). A SmartMate can be used to make this process easier and more graphical.

A Mate References is another function that can be used with standard or commonly used components. This function allows for predefined, named mates. When the references are added to an assembly, the mates are automatically created. SmartMates are used when these mates need to be created after the component is placed within the assembly, or when there are some assembly components not often reused or inserted in assemblies. These types of components do not warrant the extra work required to set up the predefined mating schemes.

A SmartMate is an assembly-mating relation created automatically. A SmartMate is created when a part--subassembly component--is dragged into an assembly or moved within an assembly. As shown in Figures 1 and 2, there are visual clues to indicate this mode.

Figure 1. Observe the cursor next to the selected boss. That's the visual clue to indicate a component has been selected.

Figure 2. Here, when adding a washer, the cursor gives a visual clue to indicate the concentric mate that has been created between two circular edges.

  • The icon next to the cursor changes its appearance. The type of cursor you see depends on the selected or inferenced geometry. When the component is selected, the cursor changes to a paper clip. As the selected component, is moved over other assembly components, the cursor will change again, based on the type of geometry selected.
  • The selected entity (such as face, edge, vertex, and so on) will be highlighted.
  • The selected component will turn transparent so other assembly components can be easily referenced.

Mates can be broken into three basic categories: geometry-based mates, feature-based mates, and pattern-based mates. Here are their definitions based on Figures 1 and 2, where a washer has been added to the highlighted boss.

  • Geometry-based Mates. As shown in Figure 2, when you select the inside edge of the washer in the part window and drag it into the assembly, as the washer is passed over the hole on the boss, the cursor changes to indicate the type of mates that will be created. When you drop the washer (by releasing the mouse button), two mates, both concentric to the holes and edges, are created automatically.
  • Feature-based Mates. In the same scenario, a feature-based mate is also created between the boss and the hole (see Table 1 for the different types of mates created and cursors displayed based on items referenced).
  • Pattern-based Mates. SmartMates can also be created by referencing a circular pattern of holes on a planar face. You align the component to match the circular edge, use the Tab key to align its patterns, and release the mouse key to drop the component into place. In this case, three mates are created: a concentric mate between the circular edges, a coincident mate between the planar faces, a concentric mate between the selected part and pattern within the assembly.

Table 1. Mate Types and Visual Clues

Steps for Creating a SmartMate

Here are the procedures for creating a SmateMate.

  • Select the SmartMate icon.
  • Double-click on the desired component face, edge, or vertex to SmartMate; the part will turn transparent.
  • Hold down the mouse button and drag the component to the desired location. The cursor will change based on what is being inferenced.
  • If the alignment of the component needs to be flipped, press the Tab key.
  • Release the mouse button.

And here are the steps for adding a new part to an assembly.

  • Tile the windows so both the part and assembly are visible.
  • Select the desired face, edge, or vertex to SmartMate.
  • Hold down the mouse button and drag the component to the desired location. The cursor will change based on what is being inferenced.
  • If the alignment of the component needs to be flipped, press the Tab key.
  • Release the mouse button.

There are a few things you should know about SmartMates. First, mates can be added as the assembly component is dropped into the assembly, eliminating the extra steps of first adding the assembly component and then manually adding additional mates. You can also add more than one mate at a time (in some cases). The selected component will turn transparent so other assembly components can be referenced. You can use SmartMates after the assembly component has been added to the assembly. If you need to temporarily suspend SmartMates while dragging, you can hold down the Alt key while you drag. To infer SmartMates, release the Alt key. You should also bear in mind that SmartMates only inference unconstrained degrees of freedom; they will not create a mate that over-defines the assembly component.

Keep in mind that the SmartMate feature shares the same PropertyManager with the Rotate and Move Components functions. So you can activate the options for the Move Component feature by deselecting the SmartMate icon. This allows you to position or rotate assembly components for easier mating. When using the SmartMate function, the other options within the PropertyManager can typically be ignored.


A SmartMate is a means to rapidly define the mating attributes for assembly components. Used in conjunction with Mate References, this feature can help reduce the time required to create assemblies.

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