Convert SLDPRT to STL

A 3D printer slicer, mesh editor, or manufacturing service may accept .stl but not a SOLIDWORKS part file. Exporting creates a printable triangle mesh for sharing, while removing the original feature history and parametric editing data.

What the SLDPRT format is

.sldprt is the native part-file format of Dassault Systèmes SOLIDWORKS. It stores a parametric model with sketches, dimensions, feature history, configurations, assigned materials, and one or more solid or surface bodies.

SOLIDWORKS uses SLDPRT files for mechanical design, product development, engineering documentation, supplier exchanges, and PDM or 3DEXPERIENCE workflows. An SLDPRT file is a part, not an assembly; assemblies normally use .sldasm and require exporting their referenced parts or the complete assembly separately.

What the STL format is

.stl describes a surface as triangular facets. Slicers, additive-manufacturing systems, mesh-repair tools, rapid-prototyping services, and many visualization applications support it.

STL is simple and broadly compatible, and binary STL is often smaller than a native CAD file. It does not retain sketches, dimensions, constraints, feature history, editable solids, assembly relationships, material definitions, or dependable color information. Standard STL also has no universally enforced unit metadata, so the receiving software must interpret the model scale correctly.

How to export with SOLIDWORKS

1. Open the part and use Ctrl+Q to force a rebuild. Resolve rebuild errors before exporting because failed or suppressed features can leave incomplete geometry.
2. Activate the required configuration if the part contains multiple configurations. Only the active configuration is normally represented by the exported mesh.
3. Select File → Save As, set Save as type to STL (*.stl), choose a destination, and select Options.
4. Choose Binary unless a specific legacy system requires ASCII. Binary STL is substantially smaller and is accepted by most current slicers.
5. Set the output units to the units expected by the receiving application, normally millimeters for 3D printing.
6. Select Fine for a general export, or choose Custom and reduce the deviation and angle tolerances when curved faces or small features need greater fidelity. Tighter tolerances create more triangles and a larger file.
7. For a multibody part, use the available body-selection or single-file options to export all required bodies or only the bodies needed by the target workflow.
8. Save the STL, then open it in the slicer or a mesh-checking application. Verify a known dimension, orientation, visible features, and whether the mesh is closed.

SOLIDWORKS is the most predictable desktop option because it reads the native model directly and controls the tessellation that generates the mesh. Menu names and available export settings vary between releases and licenses.

How to convert without SOLIDWORKS

CAD Exchanger Web can import many SLDPRT files and export STL in a browser. Upload the part, choose STL, set units and mesh quality when available, and download the result. Its supported SOLIDWORKS versions, file-size limits, and account requirements can change.

Onshape can import compatible SOLIDWORKS parts into a document. After the import completes, select the part in the Part Studio, choose the export command, set STL and the required units or resolution, and download the mesh. Import compatibility depends on the SOLIDWORKS file version and model contents.

Online services are unsuitable for confidential or unreleased designs unless their storage, deletion, encryption, and access policies satisfy the project requirements. Keep the original SLDPRT because an STL cannot recreate its design tree or parametric features.

Quality and compatibility checks

• Confirm scale: compare a known dimension in the STL with the SLDPRT. A millimeter-to-inch interpretation can produce a 25.4-fold size error.
• Balance resolution and file size: coarse tessellation makes cylinders and curved faces visibly faceted; excessively fine tessellation increases file size and may slow the slicer without improving the printed part.
• Check watertightness: a printable mesh should have closed surfaces, consistently oriented normals, and no gaps, duplicate triangles, or self-intersections. Use the slicer's repair function or a mesh utility such as MeshLab or Microsoft 3D Builder where available.
• Check small features: holes, thin walls, fillets, and embossed text can disappear when their dimensions are close to the selected tessellation or printer resolution.
• Check the output configuration and bodies: compare the STL visually with the intended SOLIDWORKS configuration and confirm that no hidden or unwanted body was exported.
• Preserve the source: archive the SLDPRT with the exported STL. The mesh contains triangles only and cannot restore constraints, dimensions, materials, or editable features.