STEP

STEP (ISO 10303) is an international standard for CAD data exchange. It preserves precise 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 major CAD software.

STEP is oriented toward engineering precision, not real-time rendering. Browsers and game engines typically require conversion to a mesh format. A suitable workflow: complete design in CAD, export STEP for archiving or collaboration, then convert to STL/GLB for previewing, printing, or Web display. The extensions .stp and .step are equivalent.