Convert PAR to Parasolid in your application
3D InterOp is a CAD interoperability SDK that lets your software read PAR 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 Solid Edge part · Writes Parasolid
- Exact geometry → exact geometry
- C++ / C# APIs
PAR 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.
| Solid Edge part (source) | Parasolid (target) | |
|---|---|---|
| Full name | Solid Edge Part | Parasolid transmit file (text X_T, binary X_B) |
| Standard / owner | Siemens | Proprietary — Siemens |
| File extensions | .par | .x_t, .x_b, .xmt_txt, .xmt_bin |
| Geometry | Exact B-Rep | Exact B-Rep |
| Assemblies / structure | Part file | Yes (Parasolid assembly structure) |
| 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 Solid Edge 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.
Why software vendors add PAR 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 PAR input: Solid Edge V18 to SE 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 a PAR (.par) file?
A PAR file is a Siemens Solid Edge part. Solid Edge is built on the Parasolid kernel and stores sheet metal parts in PSM files and assemblies in ASM files.
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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.
Yes. Writing Parasolid needs a Parasolid installation: there is no Parasolid Direct writer.
Yes. If your application uses Parasolid, a Parasolid-based Solid Edge reader is available.
3D InterOp reads Solid Edge V18 to SE 2026.
3D InterOp writes Parasolid 12 to 38.0.150.
No. 3D InterOp reads PAR but doesn’t write it. To send data back to Solid Edge users, write a neutral format they can import, such as STEP.
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Building software that needs to convert PAR to Parasolid?
3D InterOp is an SDK that lets your application read Solid Edge part and write Parasolid alongside 30+ CAD and BIM formats.