Convert SLDPRT to Parasolid in your application
3D InterOp is a CAD interoperability SDK that lets your software read SLDPRT files and write Parasolid, with exact B-Rep geometry carried across and nothing tessellated.
Spatial does not offer an online converter or a desktop conversion app. 3D InterOp is a component that software vendors embed in their own products.
- Reads SOLIDWORKS part · Writes Parasolid
- Exact geometry → exact geometry
- C++ / C# APIs
SLDPRT to Parasolid at a glance
Both formats store exact geometry, so the model stays exact. The differences are in the product data each one can carry.
| SOLIDWORKS part (source) | Parasolid (target) | |
|---|---|---|
| Full name | SOLIDWORKS Part | Parasolid transmit file (text X_T, binary X_B) |
| Standard / owner | Dassault Systèmes SOLIDWORKS | Proprietary — Siemens |
| File extensions | .sldprt | .x_t, .x_b, .xmt_txt, .xmt_bin |
| Geometry | Exact B-Rep | Exact B-Rep |
| Assemblies / structure | Part file (assemblies are SLDASM files) | Yes (Parasolid assembly structure) |
| PMI | Semantic (DimXpert) and graphical, SOLIDWORKS 2014 and later | PMI groups and attributes (3D InterOp representation) |
| 3D InterOp support | Read only | Read and write · up to Parasolid 38 |
What's preserved, what changes
Here is what your application can expect to carry across from SOLIDWORKS part to Parasolid.
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Preserved
Exact geometrySolids and surfaces stay exact B-Rep. The model is never reduced to a triangle mesh.
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Not carried
PMIParasolid has no PMI, so the PMI read from SLDPRT isn’t written. Keep STEP AP242 as an output when PMI matters.
Why software vendors add SLDPRT to Parasolid conversion
Hand models to kernel-based applications
Many CAD, CAM and CAE applications are built on the Parasolid kernel. Writing Parasolid gives them exact geometry they can load without another translation step.
Downstream modeling and analysis
An exact Parasolid B-Rep can still be edited, meshed or machined by downstream tools, which a tessellated export would not allow.
Exchange within one ecosystem
Partners whose tools share the Parasolid kernel often prefer to exchange Parasolid files directly.
Things to check before you ship
- Written Parasolid versions: Parasolid 12 to 38.0.150.
- Writing Parasolid needs a Parasolid installation: there is no Parasolid Direct writer.
- Supported SLDPRT input: SOLIDWORKS 98 to 2026.
- Validate a sample of translated files in the target system your users actually work with.

Working with Spatial was a real milestone for us: Thanks to the powerful 3DInterOp library, we were able to successfully bring our complex CAD-based solutions to the cloud while remaining flexible to meet individual customer requirements. For us, Spatial is not just a technology partner, but a true enabler of our product strategy.
Dr. Arno Michelis, Founder, Simus Systems
Read the Case StudyAbout the formats
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Source format
What is an SLDPRT (.sldprt) file?
An SLDPRT file is a SOLIDWORKS part: a single component with its exact 3D geometry, feature tree and properties. SOLIDWORKS is built on the Parasolid kernel.
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Target format
What is a Parasolid (X_T) file?
Parasolid is the geometric modeling kernel developed by Siemens and used by many CAD, CAM and CAE applications. Its transmit files store exact B-Rep models as text (.x_t) or binary (.x_b).
Frequently asked questions
Yes. Both formats store exact B-Rep geometry, so the model is translated without being tessellated into triangles.
Parasolid has no PMI, so the PMI read from SLDPRT isn’t written. When PMI matters, offer STEP AP242 as an output.
Yes. Writing Parasolid needs a Parasolid installation: there is no Parasolid Direct writer.
Yes. If your application uses Parasolid, a Parasolid-based SOLIDWORKS reader is available.
Semantic PMI from SOLIDWORKS 2014 to 2026, and graphical PMI from SOLIDWORKS 2014 onwards.
3D InterOp reads SOLIDWORKS 98 to 2026.
3D InterOp writes Parasolid 12 to 38.0.150.
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Building software that needs to convert SLDPRT to Parasolid?
3D InterOp is an SDK that lets your application read SOLIDWORKS part and write Parasolid alongside 30+ CAD and BIM formats.