Convert CATPART to IGES

A receiving CAD, CAM, inspection, or tooling system may require IGES instead of a native CATIA part file. Exporting an IGES copy allows geometry to be shared without sending the original CATIA feature history.

What the CATPART format is

.CATPart is Dassault Systèmes CATIA V5’s native part-document format. It can contain bodies, parametric features, sketches, constraints, hybrid geometrical sets, datum geometry, and links to external references. CATIA users in engineering, manufacturing, supplier, and design organizations create CATPART files during normal part modeling.

CATPART is not a neutral exchange format. Other CAD applications generally cannot edit its CATIA feature tree, formulas, constraints, or design intent as native features. A CATPart is a part document, although it can contain multiple bodies; assemblies are normally stored in .CATProduct documents.

What the IGES format is

IGES, stored with the .igs or .iges extension, is a neutral CAD exchange format supported by many legacy and current CAD, CAM, inspection, and tooling systems. It can carry wireframe entities, curves, trimmed surfaces, and, when the exporter and importer support them, solid boundary-representation entities.

IGES transfers geometry rather than CATIA’s parametric tree, sketches, constraints, formulas, feature names, or design history. For newer systems, STEP AP214 or AP242 is usually preferable for solid and assembly exchange, but IGES remains appropriate when the receiving application specifically requires it.

How to convert the file in CATIA V5

1. Open the .CATPart in CATIA V5 and run the model’s Update command if it contains outdated or unresolved features. Resolve external links and errors before exporting.
2. Confirm the part’s units and visibility. Show the body or geometry to export and hide construction elements that should not be included.
3. Review the IGES settings under Tools → Options → General → Compatibility → IGES. Select the representation supported by the recipient, such as surface or solid/B-rep output, and set the required units and tolerance where those options are available.
4. Use File → Save As and choose an IGES file type, then save the result as part.igs or part.iges. Some CATIA configurations expose the operation through File → Export instead.
5. Open the exported file in the recipient’s CAD system or in an independent CAD viewer. Check a known dimension, orientation, face count, body count, and any visible gaps before delivery.

CATIA menu names and IGES options vary by V5 release, workbench, and license. If no IGES output type is available, the installation may lack the required data-exchange license or administrator configuration.

Using desktop conversion software

CAD Exchanger Desktop and Datakit CrossManager are commercial alternatives when CATIA is unavailable. Depending on the product version and license, they can import CATIA V5 parts, export IGES, and process files in batches. Confirm the exact CATIA V5 and IGES support in the current vendor format matrix before purchasing or converting.

These tools may expose settings for units, tessellation, surfaces, solids, healing, and tolerance. Match the output to the receiving system rather than assuming that the default settings preserve a watertight solid.

Using an online converter

CAD Exchanger Cloud can be considered for nonconfidential files when its current format matrix confirms CATPart import and IGES export. Upload the file, select IGES as the output, download the result, and inspect it in a CAD viewer before sharing it.

Do not upload proprietary, regulated, or supplier-restricted models without authorization. Changing .CATPart to .igs in a file manager does not convert the data; a valid output must contain IGES entities and open in an IGES-capable application.

Quality and compatibility limitations

• Feature history is lost: IGES does not preserve CATIA sketches, constraints, formulas, Part Design features, or editable parametric intent.
• A solid may become surfaces: Some exporters or importers represent the model as trimmed surfaces rather than a watertight solid. Use the available solid or B-rep option when required, then verify that the faces form a closed shell.
• Units need verification: IGES can store unit information, but older importers may ignore or misread it. Measure a known dimension after import; a factor of 25.4 commonly indicates an inch-to-millimeter mismatch.
• Tolerance affects healing: A loose tolerance can leave gaps between adjacent faces, while an unnecessarily tight tolerance can increase processing time and file size. Use the receiving system’s specified tolerance when available.
• Assemblies need separate handling: A CATProduct assembly is not equivalent to one CATPart. Convert its component parts separately or use an assembly-aware exporter; ordinary IGES output generally does not preserve CATIA assembly structure, constraints, or product links.
• Metadata may change: Colors, layers, object names, hidden geometry, splines, PMI, and drafting views may be omitted or interpreted differently by the destination application.