A CATPART file is the native file format of CATIA V5 software. It stores parts and assemblies created in CATIA V5, a 3D CAD manufacturing application. These files can be opened and edited in CATIA V5 or other CAD applications that support the CATPART file format such as AutoCAD. A CATPART file contains the 3D geometry along with structure data of the models. It is saved to disc in binary file format and has magical number 56 35 5F 43 46 56 32.