STEP

STEP (ISO 10303) is an international standard for CAD data exchange. It preserves exact geometry using NURBS surfaces and solid modeling, widely used in mechanical design, engineering, and manufacturing. Unlike mesh formats (STL/OBJ), STEP retains parametric features and assembly structures, enabling lossless transfer between mainstream CAD software.

STEP targets engineering precision, not real-time rendering: browsers and game engines cannot display it directly, requiring conversion to mesh formats. A typical workflow: design in CAD, export STEP for archiving or collaboration, then convert to STL/GLB for preview, printing, or web display. The extensions .stp and .step represent the same format with identical content.