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What is an SLDPRT file?

An SLDPRT file contains one SOLIDWORKS part: its solid, surface or sheet metal bodies, the feature tree used to build them, sketches, reference geometry, materials, appearances and custom properties. A single file can hold several configurations, which are variants of the part with different dimensions or suppressed features.

SLDPRT is one of the main SOLIDWORKS file formats, alongside .sldasm for assemblies, .slddrw for drawings and .slddrt for templates. The format is proprietary, and SOLIDWORKS uses the Parasolid kernel to represent the exact geometry stored in it.


What data does an SLDPRT file contain?

DataDescription
GeometryExact B-rep solid, surface and sheet metal bodies
Features and sketchesThe feature tree, 2D and 3D sketches, reference planes and points
ConfigurationsVariants of the part stored in the same file
AppearanceColors and transparency at body and face level
MaterialsMaterial assignment and physical properties
PropertiesSummary information, custom and configuration-specific properties, units
PMIDimXpert dimensions and tolerances, and other annotations

What Is SLDPRT Used For? Applications and Industry Use Cases

SOLIDWORKS is used by a very large community of engineers and designers, so SLDPRT files are everywhere in mechanical design and manufacturing: industrial machinery, consumer products, medical devices, tooling and fixtures. They are sent to machine shops, 3D printing services, inspection labs and partners who work with other CAD systems.

For software developers, reading SLDPRT files lets CAM, CNC, additive manufacturing, metrology, simulation and visualization applications use SOLIDWORKS data directly, without a SOLIDWORKS license or a neutral export step. Exact geometry, names, colors, materials and PMI help these applications automate toolpath generation, measurement planning or analysis setup.


Challenges or Common Pitfalls

Configurations are a frequent source of surprises. Files re-saved in a newer SOLIDWORKS version do not always contain geometry for every configuration, so a translator can only deliver the configurations whose geometry is actually stored. Activating each configuration and saving the part again solves the problem.

Some SOLIDWORKS-specific content does not translate easily, such as externally referenced features, certain advanced holes and pattern types, or data brought into SOLIDWORKS from neutral formats without breaking the link. Identifiers used for associativity are also not guaranteed to be unique, which matters for applications that track faces and edges across revisions.


How Spatial Helps

Our 3D InterOp SDK reads SLDPRT files without requiring a SOLIDWORKS license, up to SOLIDWORKS 2026, with a choice between a direct translator and a Parasolid-based translator. It extracts the exact B-rep geometry stored in the file, along with reference work planes and points and 2D or 3D sketch curves, and supports multiple configurations.

3D InterOp also imports body, face and edge names, colors and transparency, hidden bodies on request, user-defined and configuration-specific attributes, part-level material properties and units. Since Release 2026 1.0.1, summary properties such as author, title and keywords are available, and 3D InterOp reads DimXpert PMI, including roughness and 3D views and captures added in Release 2026 1.0, as well as manufacturing features such as holes and threads.

The imported data can be translated to 3D ACIS Modeler or Parasolid, and SOLIDWORKS models are also supported by the Hidden Body Removal capability of our Data Prep technology.

Dassault Systèmes

Siemens

Autodesk

Standards

Other

  • Pro/E / Creo
  • Rhino
  • MicroStation DGN
  • AVEVA
  • Smart3D

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