Convert IGS to IPT

A supplier or legacy system may provide a model as IGES while Autodesk Inventor requires an .ipt part for editing, assemblies, or drawings. Converting it creates an Inventor document, but usually does not recover the source model’s parametric feature history.

What the IGS format is

IGS, stored as .igs or .iges, is the Initial Graphics Exchange Specification, a neutral CAD format containing entities such as wireframe curves, trimmed surfaces, and occasionally solid geometry. Mechanical CAD, CAM, inspection, supplier-exchange, and legacy engineering systems commonly use it.

IGES transfers geometry rather than the originating application’s native design structure. Sketch constraints, feature trees, assembly relationships, material definitions, and design intent are generally absent.

What the IPT format is

IPT is Autodesk Inventor’s native part-document format. It can store Inventor sketches, parameters, feature history, materials, appearances, and one or more solid bodies, making it suitable for Inventor assemblies, drawings, and downstream modeling.

An imported IGES model saved as IPT normally contains an imported-body or base-feature result, not editable Inventor operations such as the original extrusions, fillets, holes, or patterns. Those features must be recreated or modified with direct-edit tools.

How to convert IGS to IPT

Using Autodesk Inventor

1. Keep an unchanged copy of the source file and confirm whether its extension is .igs or .iges.
2. In Inventor, select File → Open, set the file type to IGES (*.igs, *.iges), and open the file.
3. Review the translator options. Set the import units explicitly if the file’s unit metadata is missing or unreliable, and choose solid, surface, or composite import according to the source geometry.
4. Inspect the result in the graphics window and model browser. If Inventor imports disconnected surfaces, use its repair and stitch tools to close gaps and create a solid where the surfaces are watertight.
5. Save the imported document with File → Save As and select Inventor Part (*.ipt). Use File → Save Copy As when the working document must remain separate from the saved copy.
6. Close and reopen the .ipt. Check units, body count, bounding dimensions, holes, wall thicknesses, and visible faces before inserting it into an assembly or using it for manufacturing.

Inventor is the most direct option when the required output is IPT because it writes the native format and can validate the imported body in the target application. Import-dialog names and available translator settings vary between Inventor releases.

Using other desktop software

FreeCAD, Rhino, SolidWorks, Creo, Siemens NX, CATIA, and similar CAD systems can often read IGES, but their ability to write a valid native .ipt varies. A practical two-stage workflow is to use one of these applications to repair the geometry and export .step, then open that STEP file in Inventor and save it as .ipt. This adds another translation and can lose additional metadata, so direct import into Inventor is preferable when it succeeds.

Using an online service

Direct browser-based IGES-to-IPT conversion is uncommon because IPT is a proprietary Inventor document format. Autodesk Fusion is a reputable cloud-connected alternative when the current account and export menu offer Autodesk Inventor .ipt; upload the IGES file, verify the units and geometry, then use the available Inventor export command. Autodesk changes supported export formats by workspace and subscription, so confirm that .ipt is listed before uploading the file.

Many online CAD converters support IGES input but output only STEP, Parasolid, STL, or another neutral format. Such a conversion is an intermediate step, not an IPT conversion: open the result in Inventor and save it as .ipt. Do not upload confidential or regulated CAD data without checking the service’s retention, deletion, access-control, and encryption terms.

Quality and compatibility limits

• Parametric history is not transferred. The resulting IPT generally contains imported geometry. Remodel the part when editable sketches and feature dependencies are required.
• Surface defects can prevent solid creation. Gaps, inaccurate edge tolerances, overlapping faces, missing trims, and duplicate entities may produce an open surface set or an incomplete body. Repair and stitch the geometry before saving.
• Verify scale and units. Measure a known dimension immediately after import. An incorrect unit interpretation can make the part consistently too large or too small and can contaminate assemblies and drawings.
• Expect metadata loss. Native constraints, feature names, assembly links, materials, custom properties, and manufacturing annotations usually do not survive the IGES exchange.
• Validate critical parts. Compare dimensions, body count, hole diameters, wall thicknesses, surface continuity, and the location of coordinate systems with the source model. Run Inventor’s geometry or error checks before production use.