Convert STP to X_T

Some CAD, CAM, and simulation systems specifically require Parasolid’s X_T format instead of STEP for downstream modeling or kernel compatibility. Converting an STP file also provides a practical way to deliver a model to a supplier or customer whose software cannot import STEP reliably.

What the STP format is

STP, more commonly called STEP, is the ISO 10303 neutral CAD exchange format. It can contain precise boundary-representation solids, surface models, curves, assemblies, product structure, colors, layers, and selected metadata, depending on the STEP application protocol and the exporting software.

Mechanical CAD systems such as SolidWorks, Siemens NX, Solid Edge, CATIA, Creo, Autodesk Inventor, Fusion, and FreeCAD commonly import or export STEP. Files normally use .stp or .step. STEP transfers geometry between different CAD systems, but it generally does not preserve the source model’s parametric feature tree, sketches, constraints, mates, or drawings.

What the X_T format is

X_T is the text-based exchange format for Siemens Parasolid, a geometric modeling kernel used by many CAD applications. It primarily stores precise Parasolid geometry and topology, including solid and surface bodies. The binary counterpart uses the .x_b extension; use .x_t when the recipient specifically requests the text format.

X_T can import more predictably than STEP into software using Parasolid or a compatible translator, but it is still an exchange file, not a native parametric project. Feature history, sketches, assembly constraints, drawings, simulation data, and much PMI are normally absent. X_T is text-based, but manually editing it is not a practical repair method.

How to convert STP to X_T

Using SolidWorks

1. Open the .stp or .step file with File → Open. In the STEP import options, select solid-body import when the model should be a solid; use surface-body import only when the source contains open or intentionally surface-based geometry.
2. Inspect the imported bodies and run import diagnostics. Repair gaps, invalid faces, or failed solid conversions before exporting.
3. Choose File → Save As, then select Parasolid (*.x_t) as the file type.
4. Open the save options and select a Parasolid version compatible with the receiving application, if SolidWorks offers that setting.
5. Save the file and reopen it in the target system. Check units, body count, dimensions, and critical interfaces.

Siemens NX and Solid Edge provide a similar workflow: open the STEP file, inspect or heal the imported model, then use Save As or Export with Parasolid text selected. The exact menu names and supported Parasolid versions depend on the software release and license.

Using CAD Exchanger

CAD Exchanger Desktop can import STEP and export Parasolid in editions that include Parasolid export. Import the file, inspect the model tree, choose File → Export, select Parasolid text or .x_t, and choose the required compatibility version when available. Confirm the installed edition and license support this output before relying on it for production conversion; format support varies between products and plans.

Using an online converter

CAD Exchanger Cloud is an option for non-confidential files when the service currently lists STEP as an input and Parasolid X_T as an output. Upload the source, choose .x_t, download the result, and validate it in the recipient’s CAD system. Other online services may advertise generic CAD conversion but omit Parasolid export or produce only .x_b, so verify the exact output extension before uploading.

Do not send proprietary designs, export-controlled geometry, personal data, or supplier files to an online service unless its security terms and your organization’s policy explicitly allow it. Desktop conversion is preferable for confidential or regulated models.

Quality and compatibility checks

The conversion first imports STEP geometry and then writes it through the converter’s Parasolid translator. Healing or rebuilding topology can alter small faces, seams, tolerances, fillets, threads, and other details even when the overall shape appears correct.

• Measure a known distance and confirm the unit system; STEP usually records units explicitly, but import settings can still cause scaling errors.
• Compare the source and result for body count, bounding box, holes, fillets, threads, mating surfaces, and required assembly components.
• Confirm whether the destination expects one X_T file, separate part files, or an assembly structure. Export options can flatten an assembly into bodies or preserve its structure differently.
• Ask for the recipient’s supported Parasolid version. A file written by a newer Parasolid release may not open in older software; select an older compatible version when the converter provides that option.
• Keep the .x_t extension unchanged and do not open, edit, or resave the file in a text editor.

For a model that must retain editable feature history, request the originating CAD system’s native file rather than relying on STEP or X_T. For geometry exchange, a validated X_T file is usually sufficient, but it does not guarantee preservation of product metadata or manufacturing annotations.