IGES (Initial Graphics Exchange Specification) was among first vendor-neutral CAD formats designed to enable interoperability between different CAD systems. The latest versions of IGES have been approved by ANSI (American National Standards Institute) and published by US PRO (U.S. Product Data Association). The latest officially approved version of the IGES standard is version 5.3 which was published in 1996. Nonetheless, IGES remains a broadly used format (along with STEP) supported by all major CAD/CAM/CAE systems such as CATIA, Autodesk Inventor, Solidworks, Solid Edge, NX, Pro/Engineer, Creo and multiple others. IGES files usually have *.igs or *.iges file name extensions.


Definition scope

The IGES standard defines the following entities:

  • 2D and 3D geometry - curves and surfaces. These include elementary geometries (lines, circles, ellipses, planes, spheres, etc), swept surfaces (surfaces of revolution, extrusion), ruled surfaces and free-form NURBS (Non-Uniform Rational B-Spline) surfaces;
  • Bounded geometries. IGES uses Trimmed Surfaces and Bounded Surface to define bounded geometries (or topologies);
  • B-Rep (Boundary Representation) entities. These include Manifold Solid B-Rep Objects (MSBO), Shell, Faces, Loops, Edge and Vertex Lists;
  • Assemblies – Groups, Subfigure Definition and Singular Subfigure Instance;
  • Colors;
  • Layers;
  • Names.

IGES also supports other data including drawings, dimensions, Finite Element Analysis (FEA) entities, Constructive Solid Geometry (CSG), etc. For more details on IGES please refer to Wikipedia or IGES specification.


IGES file view opportunities

CAD Exchanger support of IGES

CAD Exchanger allows to read and write IGES files up to the latest available version 5.3. CAD Exchanger supports import of IGES bounded geometries, B-Rep entities, colors, layers, names and assemblies, and allows to export to other formats supporting B-Rep data. CAD Exchanger also allows to export to mesh formats using tessellated representations of input B-Rep.

Thus, CAD Exchanger supports the following scenarios: Importing (reading) and viewing IGES files.

Importing (reading) from IGES:

  • Convert IGES files (.igs, .iges) to STEP (.stp, .step);
  • Convert IGES files (.igs, .iges) to JT (.jt);
  • Convert IGES files (.igs, .iges) to ACIS (.sat);
  • Convert IGES files (.igs, .iges) to Parasolid (.x_t, .x_b);
  • Convert IGES files (.igs, .iges) to BRep (.brep);
  • Convert IGES files (.igs, .iges) to STL (.stl);
  • Convert IGES files (.igs, .iges) to VRML (.wrl);
  • Convert IGES files (.igs, .iges) to X3D (.x3d);
  • Convert IGES files (.igs, .iges) to OBJ (.obj).


Exporting (writing) to IGES:

  • Convert STEP files (.stp, .step) to IGES (.igs, .iges);
  • Convert JT files (.jt) to IGES (.igs, .iges) *
  • Convert ACIS files (.sat) to IGES (.igs, .iges)
  • Convert Parasolid files (.x_t, .x_b) to IGES (.igs, .iges)
  • Convert BRep files (.brep) to IGES (.igs, .iges)


Note: conversion of mesh formats to IGES is impossible. For instance, it is impossible to convert STL (.stl), VRML (.wrl), X3D (.x3d), or OBJ (.obj) files to IGES. In JT to IGES conversion, only parts with B-Rep representations are converted. Parts having only mesh representations are ignored.


IGES support for software vendors

Software vendors can use CAD Exchanger SDK to extend their C++ and C# applications to read, write, convert, visualize, analyze, triangulate or otherwise process IGES files.For details about IGES support by CAD Exchanger SDK please refer to the User’s Guide. For free evaluation of SDK please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it..

See how other companies leverage IGES format with the help of CAD Exchanger SDK

Simlab Soft

"CAD Exchanger/ACIS translator works great and we advise our users to use it over other formats, including STEP and IGES."


Ashraf Sultan, CEO Simlab Soft

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"With the CAD Exchanger SDK we were able to efficiently implement IGES to STL conversion. This was exactly the solution we needed and it works extremely well with virtually all the IGES files we tested."


Michal Orych, Project Manager,
FLOWTECH International AB

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