What is Coincident Mate in SolidWorks: Definition and Usage

In SolidWorks, a coincident mate aligns two selected entities so they share the same position or plane. It fixes points, edges, or faces together, making them touch or overlap exactly in 3D space.

How It Works

A coincident mate in SolidWorks works like placing two objects so they touch perfectly at a point or along a line. Imagine putting two puzzle pieces together so their edges line up exactly; the coincident mate does the same by forcing selected parts to share the same location.

For example, if you select a point on one part and a point on another, applying a coincident mate will move one part so both points overlap exactly. This keeps the parts connected as you move or rotate them, just like sticking magnets together at a single spot.

This mate is simple but powerful because it controls how parts fit and move relative to each other in an assembly, ensuring precise alignment without gaps or overlaps.

Example

This example shows how to create a coincident mate between two points using SolidWorks API VBA code. It selects two points and applies the mate to align them.

vba

Dim swApp As Object
Dim swModel As Object
Dim swAssembly As Object
Dim swMate As Object

Set swApp = Application.SldWorks
Set swModel = swApp.ActiveDoc
Set swAssembly = swModel

' Select first point
swModel.Extension.SelectByID2 "Point1", "SKETCHPOINT", 0, 0, 0, False, 0, Nothing, 0
' Select second point
swModel.Extension.SelectByID2 "Point2", "SKETCHPOINT", 0, 0, 0, True, 0, Nothing, 0

' Add coincident mate
Set swMate = swAssembly.AddMate3(1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)

If Not swMate Is Nothing Then
    MsgBox "Coincident mate created successfully"
Else
    MsgBox "Failed to create mate"
End If

Output

Coincident mate created successfully

When to Use

Use a coincident mate when you want two parts or features to touch exactly without any gap or offset. It is ideal for aligning edges, faces, or points that must be flush or connected.

For example, when assembling a bolt into a hole, you can use a coincident mate to align the bolt's axis with the hole's axis. Or when placing a bracket on a flat surface, use a coincident mate to make the bracket's face sit perfectly on the surface.

This mate helps maintain design intent and ensures parts move correctly relative to each other in assemblies.

Key Points

• A coincident mate aligns two entities so they share the same position or plane.
• It works with points, edges, faces, or vertices.
• It is used to make parts touch or overlap exactly in assemblies.
• It helps control part movement and positioning precisely.
• Commonly used for aligning holes, edges, and surfaces.

Key Takeaways

A coincident mate forces two selected entities to share the same location or plane in SolidWorks.

It is useful for aligning points, edges, or faces so parts fit together perfectly.

Use it to control how parts connect and move in assemblies without gaps.

It is commonly applied to align holes, surfaces, or edges in mechanical designs.