IGES (Initial Graphics Exchange Specification)

IGES is the long-standing neutral CAD data exchange format for 2D drawings and 3D wireframe/surface geometry, originally a US Air Force ICAM project that became ASME/ANSI Y14.26M in 1989. CIMdata: “A standard for interchanging electronic data among CAD/CAM systems including geometry, dimensions, notes, and tolerances.” IGES 5.3 (1996) is the last revision; the standard is effectively frozen and being displaced by STEP AP242.

Scope

• Wireframe, surface, and limited solid geometry (post-IGES 5.x B-rep entities).
• 2D drawings, dimensions, and annotations.
• ASCII and binary file representations (.igs / .iges).
• Color, layer, view, and font entities.

Why it still appears

Three reasons IGES persists in 2026 despite STEP’s superiority:

1. Tooling/CAM legacy — many shop-floor CAM and inspection systems read only IGES.
2. 2D drawing exchange for sub-suppliers running older CAD.
3. Conservative supplier contracts that name IGES specifically.

Relationships (see sidebar)

• Normative for CAD 3D Design and CAD 2D Drafting interchange.
• Competes with STEP for the same role (and increasingly loses to STEP); not directly comparable to JT, which is a visualization format rather than an authoring interchange format.

Steward

US PRO (US Product Data Association); Y14.26M maintained by ASME.