An X_T file is a model part file created by Parasolid, a CAD geometric modeling program. It contains 3D model data such as geometry, topology, and color. X_T files are designed as a standard export format for sharing Parasolid CAD models.

X_T files are used by the standard, Translators, and Bodyshop editions of Parasolid, and are used in place of older version XMT_TXT and XMP_TXT files. The X_T files are saved in text format and can be exported and imported using a variety of other CAD programs. X_T files may also be saved in binary format in .X_B files, which are less common than X_T files.