Convert Parasolid to STP in your application
3D InterOp is a CAD interoperability SDK that lets your software read Parasolid files (X_T, X_B) and write STEP AP203, AP214 or AP242, with exact B-Rep geometry carried across.
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 Parasolid · Writes STEP
- Exact geometry → exact geometry
- C++ / C# APIs
Parasolid to STP at a glance
Both formats store exact geometry, so the model stays exact. The differences are in the product data each one can carry.
| Parasolid (source) | STEP (target) | |
|---|---|---|
| Full name | Parasolid transmit file (text X_T, binary X_B) | Standard for the Exchange of Product model data |
| Standard / owner | Proprietary — Siemens | ISO 10303 — AP203, AP214, AP242 |
| File extensions | .x_t, .x_b, .xmt_txt, .xmt_bin | .stp, .step |
| Geometry | Exact B-Rep | Exact B-Rep |
| Assemblies / structure | Yes (Parasolid assembly structure) | Yes |
| PMI | PMI groups and attributes (3D InterOp representation) | Graphical and semantic (AP242) |
| 3D InterOp support | Read and write · up to Parasolid 38 | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from Parasolid to STEP.
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Preserved
Exact geometryParasolid solids and surfaces are written to STEP as exact B-Rep.
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Preserved
Assembly structureThe STEP writer supports assemblies, so a Parasolid assembly keeps its structure in STEP.
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Changes
STEP versionThe STEP writer writes AP214 by default. Your application can choose AP203, AP214 or AP242 to match the systems your users exchange with.
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Not carried
Assembly instance layersThe STEP writer cannot write layer information set on assembly instances.
Why software vendors add Parasolid to STP conversion
Supplier and OEM exchange
STEP is the ISO standard most supply chains specify for exchanging 3D models. Writing it lets your users send data to partners on any CAD system.
Model-based definition
STEP AP242 can carry semantic PMI next to exact geometry, so your users can share models together with their manufacturing data.
Long-term archiving
As an ISO standard independent of any CAD vendor, STEP is widely used to archive product data.
Things to check before you ship
- Set the STEP version explicitly if your users need AP203 or AP242: the default is AP214.
- Semantic PMI is written to STEP AP242 only, and requires a license in addition to the STEP Writer.
- Test with multi-body parts and assemblies from the Parasolid-based applications your users work with.
- 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 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).
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Target format
What is a STEP (.stp) file?
STEP is the ISO 10303 standard for exchanging 3D product data between CAD systems. Its application protocols range from exact geometry (AP203, AP214) to full model-based definition with PMI (AP242).
Frequently asked questions
Yes. Parasolid solids and surfaces are written to STEP as exact B-Rep, with no tessellation.
The STEP writer supports AP203, AP214 and AP242, with AP214 as the default. Your application sets the version at export, and semantic PMI is written to AP242 only.
3D InterOp reads Parasolid 9.0 to 38, in text (.x_t, .xmt_txt) and binary (.x_b, .xmt_bin) form.
Yes. The STEP writer supports assemblies, so a Parasolid assembly keeps its structure. Layers set on assembly instances aren’t written.
Yes. 3D InterOp reads and writes both formats. Writing Parasolid needs a Parasolid installation.
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Building software that needs to convert Parasolid to STP?
3D InterOp is an SDK that lets your application read Parasolid and write STEP alongside 30+ CAD and BIM formats.