How to snap two parts together in SolidWorks?
Short Answer
To snap two parts together in SolidWorks, use Mate in an assembly and apply the most common relationship, such as Coincident, Concentric, or Distance, between matching faces, edges, or axes. This is the standard professional method for positioning components accurately. Limitation: parts must already be inserted into the same assembly.
What You Need to Know Before
Warning: if both components are Fixed, or if one part is fully defined by existing mates, SolidWorks may not let the new mate solve correctly. A very common failure is trying to mate imported geometry with missing reference planes, axes, or clean cylindrical faces.
How to snap two parts together in SolidWorks
Command: Mate
Shortcut: M
Quick Steps:
- Open the assembly, then go to the CommandManager Assembly tab and click Mate, or press M.
- Select the two faces, edges, vertices, or axes you want to align; SolidWorks will preview common mate types automatically.
- In the Mate PropertyManager, choose the correct relation such as Coincident or Concentric, check Aligned or Anti-Aligned if needed, then click the green check.
Variables & Settings
Key Setting: Lock Rotation for Concentric mates
Expert Setting: when creating a concentric mate, enable Lock Rotation if you need the two parts to snap together without allowing free spinning around the shared axis. Leave it off for shafts, rollers, or hardware that must still rotate.
Why it Fails
Cause 1 (Geometry): the selected faces are not compatible for the mate type, such as trying to make non-cylindrical faces concentric or using distorted imported geometry.
Cause 2 (layers/Locks): one component is Fixed, or the assembly already contains locking mates that prevent movement needed to solve the new mate.
Cause 3 (Command/Logic): the mate combination is over-defining the assembly, conflicting with existing Coincident, Distance, or Angle mates.
Quick Fix & Best Practice
Quick Fix: right-click the component in the FeatureManager and choose Float, then edit or suppress the conflicting mate and reapply Mate with the correct relation.
Manager’s Verdict: use standard mates first—Coincident, Concentric, Parallel, and Distance—because they are faster to solve, easier to troubleshoot, and more reliable than stacking complex mate logic too early.
FAQ
Can I snap parts together automatically in SolidWorks?
Yes, SmartMates can speed this up, but Mate is still the most controlled and common professional method.
Why won’t my parts move into position when I add a mate?
Usually one component is Fixed or existing mates are blocking the movement.
What mate is best for a pin and hole?
Use a Concentric mate first, then add a Coincident or Distance mate to set the axial position.
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