# Siemens NX File Tools: PRT Viewer & STEP Converter

Open Siemens NX / UG NX PRT files online, identify ambiguous PRT sources, package assembly references and convert supported geometry to STEP.

This hub collects CADProps workflows for Siemens NX / UG NX PRT files.

The first important point is that **PRT is not unique to NX**. Confirm the authoring application when the source is uncertain before selecting an NX-specific workflow.

## Open NX PRT files online

Use the [NX PRT viewer](https://www.cadprops.com/tools/nx-viewer/index.md) to inspect supported files and check dimensions, bodies and assembly scope.

For assemblies, package referenced PRT files in a ZIP while preserving relative paths.

## Convert NX PRT to STEP

Use the [NX to STEP converter](https://www.cadprops.com/tools/nx-to-step/index.md) when the next workflow needs neutral geometry. NX files are mostly shown from the display geometry saved in the file, so the export is a mesh STEP: triangles for review and overall size, not exact NX surfaces for machining. A part whose saved Parasolid partition rebuilds into closed, valid solids that agree with the saved display gives an exact STEP instead; many NX parts do not qualify yet. Ask for a STEP export from NX when the recipient needs a solid and the result is a mesh.

A successful conversion should still be checked for units, body/component count, placements and critical geometry.

## NX guides

- [How to open an NX PRT file without Siemens NX](https://www.cadprops.com/guides/open-nx-prt-without-nx/index.md)
- [NX or Creo PRT? Identify the source](https://www.cadprops.com/guides/prt-file-nx-or-creo/index.md)
- [How to convert NX PRT to STEP](https://www.cadprops.com/guides/nx-prt-to-step/index.md)
- [CAD conversion checklist](https://www.cadprops.com/guides/cad-conversion-checklist/index.md)

## Assembly completeness

A top-level PRT can depend on other components. Missing references can leave a plausible-looking partial assembly.

Do not treat dimensions, volume or mass as complete assembly totals until the loaded scope is understood.

## What to verify

1. Confirm the PRT actually comes from Siemens NX.
2. Record the source release when compatibility matters.
3. Keep assembly dependencies together.
4. Verify one known dimension and units.
5. Inspect important holes, pockets or mating faces.
6. Reopen STEP output in the receiving workflow when practical.

## Native history is different from neutral geometry

STEP is useful for cross-CAD exchange but does not reconstruct NX sketches, expressions or feature history.

Keep the native NX source when parametric editing or design traceability matters.

## Related resources

See the [format compatibility matrix](https://www.cadprops.com/supported-formats/index.md) and [CAD sample files](https://www.cadprops.com/examples/index.md) for known-good test cases.

HTML page: https://www.cadprops.com/siemens-nx/