CAD Glossary
IGES File Format
Initial Graphics Exchange Specification — neutral CAD format for geometry exchange between CAD systems.
[REVIEW: content pending from Alex]
IGES (Initial Graphics Exchange Specification, ANSI Y14.26M) is a neutral CAD format for exchanging geometric data between different CAD systems. Predating STEP, IGES remains in wide use, particularly in aerospace and legacy workflows.
Key characteristics
- Supports surface geometry (NURBS), wireframe, and solid representations
- Less precise than STEP for solid model exchange — surfaces may not be fully closed
- Widely accepted by all major CAD systems (SolidWorks, Inventor, AutoCAD, CATIA, NX)
- File extension:
.igsor.iges
IGES vs STEP
STEP AP214 is generally preferred for new work. IGES is commonly encountered in:
- Legacy files from the 1990s–2000s
- Supplier deliverables from older CAD systems
- Aerospace supply chains with established IGES workflows