Convert CATPART to SLDPRT

SolidWorks requires an .SLDPRT part when a CATIA model must be edited, checked, or inserted into a SolidWorks assembly. Conversion is also useful when the recipient does not have CATIA or when the design must be archived in a SolidWorks-based workflow.

What the CATPART format is

.CATPart is CATIA V5’s native format for a single part. CATIA users in aerospace, automotive, machinery, and industrial design use it for models containing bodies, sketches, surfaces, features, parameters, design history, and references to other CATIA documents.

A CATPART is not a neutral interchange file. Its feature tree, constraints, formulas, and knowledge-based design data depend on CATIA. A different CAD system may import only the resulting boundary-representation geometry.

What the SLDPRT format is

.SLDPRT is SolidWorks’ native part-document format. It can store SolidWorks features, sketches, configurations, appearances, materials, custom properties, and references used by assemblies and drawings.

Converting a CATPART normally produces an imported solid or surface body inside an SLDPRT, not a native SolidWorks feature tree. SolidWorks features can be added after import, but the original CATIA history usually must be rebuilt manually.

How to convert with SolidWorks

1. Use a SolidWorks release whose CATIA V5 translator supports the source CATPART version. Translator availability and supported CATIA releases depend on the SolidWorks edition and version.
2. In SolidWorks, open Tools → Options → System Options → Import. Enable 3D Interconnect if you want a linked reference to the CATIA source; disable it for a conventional imported-body workflow. The option name and behavior can vary by release.
3. Choose File → Open, select the CATIA V5 file type or enable automatic detection, and open part.CATPart.
4. Inspect the imported bodies for missing faces, open surfaces, incorrect units, and unexpected body count. If SolidWorks reports import errors, run Tools → Evaluate → Import Diagnostics where available.
5. Choose File → Save As, select SolidWorks Part (*.SLDPRT), and save under a new filename.
6. If 3D Interconnect created a linked feature and an independent document is required, use that feature’s context-menu command to break or dissolve the link when the installed SolidWorks release provides it. Breaking the link prevents later source updates.

How to use CATIA and STEP as a fallback

Use this method when SolidWorks cannot open the CATPART directly. STEP transfers CAD geometry more consistently between systems, but it generally does not preserve CATIA’s parametric history.

1. Open part.CATPart in CATIA V5.
2. Choose File → Save As and export part.step or part.stp. Select STEP AP242 or AP214 when the receiving system supports it; AP203 is useful for older systems but carries less product information.
3. In SolidWorks, choose File → Open and select the STEP file.
4. In the import options, select solid-body import when available and enable healing or geometry checking.
5. Run Tools → Evaluate → Import Diagnostics and repair faulty faces if SolidWorks identifies them.
6. Save the checked result as part.SLDPRT with File → Save As.

Other conversion tools

Datakit CrossManager is a commercial desktop and batch translator that supports many CATIA and SolidWorks workflows. CAD Exchanger Desktop and its cloud service can be useful for supported CAD-format combinations; confirm in the current format matrix that CATIA V5 input and SLDPRT output are both available before uploading or purchasing.

Online services are appropriate only for non-confidential models. Uploading supplier, aerospace, medical, or proprietary designs can violate contractual or security requirements. If a service cannot produce SLDPRT directly, export STEP and open that file in SolidWorks instead. Check the service’s maximum file size, CATIA version support, output options, and deletion policy.

Quality and compatibility limits

• Feature history is usually lost. Direct translation and STEP normally transfer boundary-representation geometry, not CATIA sketches, constraints, formulas, design tables, or feature operations.
• Check units, coordinate orientation, body count, hole sizes, fillets, threads, wall thicknesses, and surface continuity. A model can look correct while containing invalid or disconnected faces.
• CATIA assembly references, publications, external links, knowledge rules, parameters, annotations, PMI, and some material information may not transfer. A CATPART with external references may also require its linked CATIA documents.
• Compare critical dimensions with the CATIA source before using the result for manufacturing, tooling, CNC programming, or released drawings.
• Keep the original CATPART and any intermediate STEP file. Save the converted SLDPRT separately so the source records remain unchanged.