How to Mirror an Assembly or Sub-Assembly in SOLIDWORKS

Mirroring an assembly or sub-assembly creates opposite-hand components or mirrored placement from existing assembly geometry. It is useful for left-hand and right-hand versions, symmetrical machines, brackets, guards, and paired mechanisms.

Before using the command, decide whether you need mirrored geometry or only mirrored placement. That choice affects whether SOLIDWORKS reuses existing files or creates new opposite-hand part files.

This decision should be made before release, not after drawings are created. Changing from reused parts to opposite-hand parts later can affect BOMs, part numbers, and purchasing.

Start the Mirror Components command

1. Open the assembly.
2. Choose Insert > Mirror Components.
3. Select the mirror plane or planar face.
4. Select the components or sub-assembly to mirror.
5. Choose whether to create opposite-hand versions or reuse existing components.
6. Review the preview and accept the feature.

Choose reused or opposite-hand parts

If a component is symmetrical, you may be able to reuse the same part. If it has handed features, create an opposite-hand version. This decision affects file names, drawings, BOMs, and future edits.

For purchased hardware, reused components are usually correct. For brackets, covers, or machined parts with asymmetric features, opposite-hand versions are often required.

Look for countersinks, text, keyed holes, bends, and mounting patterns. These details often determine whether a mirrored part can truly reuse the original file.

Check mates after mirroring

Mirrored components may need mate review. Some mates transfer cleanly, while others need repair because the mirrored geometry or orientation changed. Drag the assembly gently and rebuild before trusting the result.

Check concentric mates, width mates, limit mates, and any mate that references a face direction. Mirroring can change the face orientation enough that a mate needs to be reselected.

After mate repair, drag the mirrored side gently through any expected motion. This helps catch mirrored mechanisms that look correct but do not move correctly.

Name mirrored files clearly

When creating opposite-hand parts, use names that show the relationship to the original part. Add left-hand, right-hand, mirrored, or another company-approved suffix so the files are easy to identify in drawings and PDM.

Save mirrored files in the correct project folder right away. Leaving them in a temporary location can create broken references when another user opens the assembly.

If you use PDM, check the new mirrored files into the vault with the rest of the assembly. Do not leave opposite-hand parts only in a local working folder.

Troubleshooting

If the mirrored assembly is wrong, check the mirror plane first. If file references are confusing, review the created part names and save locations. If mates break, repair them before releasing drawings or BOMs.

After the mirror is complete, check the BOM. Opposite-hand components may need unique part numbers, while reused components should usually keep the same part number.