.iges File — Initial Graphics Exchange Specification

IGES (Initial Graphics Exchange Specification) is a vendor-neutral CAD data exchange format standardized as ANSI Y14.26M. IGES files use a text-based format to represent 3D and 2D geometry including points, lines, arcs, NURBS curves and surfaces, trimmed surfaces, solid models, finite element meshes, annotations, and dimensions. The format was one of the first successful standards for exchanging CAD data between different software systems, first published in 1980. IGES files use a fixed-format 80-column structure inherited from punch card conventions, with five sections: Start, Global, Directory Entry, Parameter Data, and Terminate. While IGES has been officially superseded by the STEP standard (ISO 10303) which offers better support for modern CAD features and product data management, IGES remains widely used in manufacturing, aerospace, and automotive industries for its broad compatibility. Many CNC machines, CAM software, and legacy CAD systems support IGES as a reliable interchange format. The format is particularly common for exchanging surface geometry and 2D drawings between different CAD platforms when STEP support is unavailable or when dealing with older systems.