THE FILE FIELD GUIDE

.iges

IGES CAD Exchange Data

CAD & 3D

IGES exchanges geometry between CAD systems and also uses the IGS suffix. Displayed surfaces are not necessarily a closed solid; check units, tolerance and surface joins after import.

Main use: Exchange curves and surfaces between CAD systems
Data type: Text data

All sections, questions and sources

Content reviewed：2026-10-19 · Editor：Kai

Opening steps

Choose your environment or purpose to see its steps.

IGES-capable CAD such as Rhino

Preserve the original and inspect a working copy in a compatible application.

Open/import a copy in compatible CAD.
Inspect units/import settings and measure a known dimension.
Inspect surfaces, trims and joins, then save a working master.

Inspect the received file and its requirements

Establish dependencies and settings before proceeding.

Identify the producer, IGES version and recommended settings.
Decide whether a solid or only surfaces are required.
Agree on units and model tolerance.

Menu labels and support vary by app, OS and version. Preserve the original before making changes.

Troubleshooting by symptom

Large scale mismatch: inspect unit conversion.
Gaps: inspect source geometry, tolerance and trims.
Meshes absent: check element types supported by the exporter.
Names/text differ: inspect encoding and importer support.

IGES → STEP / native CAD / STL

Check surface connectivity before exporting suitable CAD or mesh data.
Reopen to verify scale, key dimensions, missing faces and required closed geometry.

Re-export does not restore missing geometry/history; STL tessellates surfaces.

Visible geometry versus usable manufacturing geometry

A smooth-looking model can contain open edges or duplicate faces. Check solid status/dimensions before manufacturing and document changes from the original.

Source for these steps：McNeel · IGES import/export / McNeel · Index of import/export file types

Worked example: checks before handoff

Example: measure enclosure size and hole positions, inspect joins, export STEP and reopen for comparison.

Source for these steps：McNeel · IGES import/export / McNeel · Index of import/export file types

Related-format differences

Related-format differences
Format / method	Purpose and preserved information
.iges	Exchange curves and surfaces between CAD systems
STEP / STL	STEP is CAD exchange and STL mesh; neither guarantees identical IGES information.
IGES → STEP / native CAD / STL	Re-export does not restore missing geometry/history; STL tessellates surfaces.

Handling and security

Review disclosure conditions for design and embedded author information.

Questions and answers

Is IGS different?

IGS is another suffix for IGES; confirm actual content/source.

Is STEP always more accurate?

Results depend on exported elements, settings and implementation; test exchange and dimensions.

Do visible surfaces imply a solid?

It may be an open collection of surfaces; inspect open edges and joins.

Format facts: name, steward and MIME type

Formal name: IGES CAD Exchange Data
Steward / specification: McNeel
MIME type: Consult the producer or delivery system. The extension alone does not establish a MIME type.

Primary and official sources

Software documentationIGES import/export
Units, tolerances, surfaces and mesh exchange limitations.
McNeel · Link checked：2026-10-16
Software documentationIndex of import/export file types
Rhino file formats and import/export plug-ins.
McNeel · Link checked：2026-10-16