Convert IAM to IGES

An older CAD, CAM, CNC, or inspection system may accept IGES but not Autodesk Inventor’s native assembly files. Converting makes the assembly geometry available to that system, although the Inventor assembly structure and design intelligence usually cannot be retained.

What the IAM format is

IAM is Autodesk Inventor’s assembly format. It stores component references, placements, constraints, assembly-level properties, and appearance overrides; the referenced component geometry normally remains in separate .ipt part files, with subassemblies stored as additional .iam files.

Inventor assemblies are used in mechanical design, manufacturing, supplier exchange, and product archives. An IAM file may not open correctly when referenced IPT files, subassemblies, design data, or project paths are missing. Copy the complete referenced file set before conversion.

What the IGES format is

IGES (Initial Graphics Exchange Specification) is a neutral CAD exchange format identified by .igs and .iges extensions. It can contain wireframe curves, trimmed surfaces, and, depending on the exporter, solid entities such as boundary-representation models.

IGES remains useful for legacy CAD, CAM, CNC, inspection, and surface-modeling applications because many systems support it. It generally does not preserve Inventor feature history, parametric dimensions, constraints, assembly mates, browser structure, materials, or the complete assembly hierarchy. IGES is also more likely than modern STEP exports to represent a model as separate trimmed surfaces. If the receiving system supports STEP, AP242 is usually preferable for solid geometry, colors, and assembly structure.

How to convert the files in Inventor

1. Copy the top-level IAM, every referenced IPT and subassembly IAM, and the relevant Inventor project or design-data files to a working folder. Open the assembly and resolve all missing references before exporting.
2. Decide whether the recipient needs separate components or one geometry file. For separate components, open each required IPT and export it individually.
3. For a single-file result, create a derived or simplified part from the assembly. Depending on the Inventor release, use the assembly’s Simplify workflow or create a new part and use Derive to reference the assembly. Suppress hardware, internal details, construction geometry, and other items that should not leave the design.
4. Open the resulting IPT, confirm that the intended bodies are visible, and check holes, openings, surfaces, and overall dimensions. Save a copy rather than modifying the source design.
5. Use File → Export → CAD Format, choose IGES (*.igs, *.iges), set the required units and available IGES options, and save the output. Some Inventor releases expose the same translator through File → Save As → Save Copy As.
6. Inventor releases that expose an IGES translator for assemblies may export the assembly directly, but the result is geometry-only and may contain separate bodies or surfaces instead of a usable assembly hierarchy. Deriving a controlled part or exporting component IPT files gives more predictable results.
7. Open the IGES file in the recipient’s CAD, CAM, or inspection software. Verify scale, component count, body count, holes, mating interfaces, and surface closure before using it for manufacture or measurement.

Renaming .iam to .igs does not convert the data; the file must pass through a CAD translator.

Other conversion tools

CAD Exchanger Desktop and Datakit CrossManager are commercial alternatives that can translate supported Inventor assemblies and parts to IGES. Import the complete referenced file set, select IGES as the output, configure units and tessellation or healing options where available, and inspect the result. Confirm support for the particular Inventor release and assembly features before purchasing.

CAD Exchanger Cloud can be used for an online conversion when its current format matrix accepts the IAM and its referenced files. Upload only non-confidential designs, because online services can impose file-size, assembly-depth, conversion-option, and retention limits. If the service cannot resolve external IPT references, package the referenced files as required by its upload workflow or convert the parts separately.

Quality and compatibility limits

IAM-to-IGES conversion can discard assembly hierarchy, constraints, feature history, materials, parameters, metadata, and Inventor-specific properties. Small gaps, invalid trims, missing faces, duplicate surfaces, or a solid split into surface patches can appear during translation. A receiving application may need to sew or heal the surfaces before it recognizes a solid.

Set the output units explicitly and compare a known dimension after import; an inch-to-millimetre mismatch can produce a valid-looking model at the wrong scale. Use a conversion tolerance appropriate to the manufacturing or inspection requirement, and avoid exporting hidden or unresolved geometry. Keep the original IAM, IPT, and project files as the authoritative design because IGES is an exchange copy, not a reversible replacement for the Inventor assembly.