Convert Parasolid
to STEP.

Updated 2026-10-06

To convert Parasolid to STEP, drop the .x_t or .x_b file into the converter below and download the .step. It is an exact translation: planes, cylinders and NURBS faces arrive as the same surfaces, not as facets. Nothing is installed, and no account is needed for up to 2 solid conversions a day. If you already have SOLIDWORKS, Solid Edge or NX, opening the .x_t there and saving it as STEP does the same job.

2 solid-geometry conversions a day with no account. No card, no install.

No account needed
Drop a Parasolid file.x_t / .x_b · up to 200 MB

On our servers. No account: deleted within 24 hours. Signed in: kept until you delete them. Never shared or used for training.

ResultExact

Parasolid and STEP both store B-rep geometry, so planes, cylinders, cones and NURBS survive and dimensions, radii and tangency are preserved exactly.

ChangesParasolid → STEP

What changes between Parasolid and STEP

Very little about the shape. A Parasolid transmit file is a modelling kernel writing out its own solid; STEP (ISO 10303) is the neutral standard for the same kind of data. Both describe a part as faces lying on true surfaces, bounded by edges on true curves, so a hole stays one cylindrical face whose radius you can measure, a fillet stays a fillet, and no dimension moves.

What changes is who can open it. SOLIDWORKS, Solid Edge and NX read .x_t and .x_b natively, but plenty of software does not, FreeCAD and most other OpenCASCADE-based tools among them. Nearly every CAD, CAM and inspection program reads STEP, which is usually the whole reason for converting.

What does not travel: there is no feature history on either side, because a transmit file is already a finished solid rather than a recipe, and the STEP carries the geometry, not colours or attributes. .x_t is the text encoding and .x_b the binary one; they hold the same solid and convert to the same STEP.

HowThree steps
  1. Drop your .x_t file above — up to 200 MB without an account.
  2. STEP is already selected as the output.
  3. Download the .step. Without an account, files are deleted within 24 hours; signed in, they are kept until you delete them.
FormatsWhat you are holding

Parasolid transmit file (.x_t / .x_b)

Parasolid is the modelling kernel under SOLIDWORKS, Solid Edge and NX, and a transmit file is its exact solid geometry. Between systems that share the kernel it often survives better than a neutral format. .x_t is text, .x_b is binary; both hold the same solid.

Someone in a Siemens or SOLIDWORKS shop sent you an .x_t and nothing you have opens it.

STEP file (ISO 10303) (.step / .stp)

STEP (ISO 10303) is the closest thing engineering has to a universal solid format. It stores exact B-rep geometry — a hole is a cylindrical face, not a ring of facets. Fusion 360, Inventor, Onshape, SOLIDWORKS, Creo, NX, CATIA and FreeCAD all read it; .step and .stp are the same format. AP242 supersedes AP203 and AP214.

What you send when the other side has to keep modelling, quote machining, or open the shape in a different CAD system.

Questions12 answered
How do I convert x_t to STEP online?
Drop the .x_t on this page, where STEP is already selected, and download the .step when it finishes. Files up to 200 MB need no account and nothing is installed.
How do I convert an x_b file to STEP?
The same way. .x_b is the binary encoding of a Parasolid solid; drop it in as you would an .x_t and the STEP that comes back is the same.
What if the Parasolid file will not convert?
A few surface types, variable-radius blends among them, are not rebuilt yet. When the converter meets one it stops and names it rather than writing a damaged file, and the attempt does not count against your free conversions. Ask the sender for a STEP export instead; every Parasolid-based system writes one.
Will I find out if the file was already broken?
Yes. Every conversion from Parasolid checks the file you uploaded, and if it already had invalid faces or open shells the result says so, so a fault in the original is not mistaken for one the conversion caused.
Should I send a supplier Parasolid or STEP?
STEP, unless they work in SOLIDWORKS, Solid Edge or NX and ask for Parasolid by name. Between systems that share the kernel a transmit file can be the more faithful handover; for everyone else STEP is the file that opens.
Is the Parasolid to STEP converter free?
Yes. 2 solid-geometry conversions a day with no account, of 5 in total. A free account converts 4 solid files a day and adds 25 credits. No card.
Will the STEP file keep exact curves and holes?
An exact translation: nothing is tessellated in either direction. Parasolid and STEP both store B-rep geometry, so planes, cylinders, cones and NURBS survive and dimensions, radii and tangency are preserved exactly.
Will the STEP file open in Fusion 360, Inventor or Onshape?
Yes. STEP is read directly by Fusion 360, Inventor, Onshape, SOLIDWORKS, Creo, NX and FreeCAD. It arrives as a solid body you can measure, mate and cut.
Does it read both .x_t and .x_b?
Yes. Text (.x_t) and binary (.x_b) hold the same solid, and both convert here.
How big a file can I convert?
To a mesh format like STL: 300 MB with a free account, 200 MB without one. To STEP, Parasolid or SLDPRT: 140 MB, because rebuilding a solid takes about twice the memory of writing a mesh. Maker and Studio convert up to 830 MB and 380 MB — a large conversion on a paid plan gets the server to itself.
Is it safe to upload my Parasolid file?
Files travel encrypted and are processed by machine on our own servers — no third parties, no ads or trackers, no AI training.
Is my Parasolid file deleted after converting?
Without an account, the upload and the result are deleted within 24 hours. With an account, both stay in your files until you delete them; deleted files leave our servers within 24 hours.
Beyond convertingSame file, four workspaces

Keep the part open: fill it with a lattice, check it with FEA, texture a surface, or slice it into cut-ready sheets. These workspaces are in early access — create an account, then apply from inside the app.

Create free account See pricing

ReadWhy this works the way it does
AlsoOther ways in
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Going the other way? Convert STEP to Parasolid.

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