For the Dremel 8220 vise project, the key distinction is between a true CAD solid and a triangulated mesh. Onshape’s current supported-format list explicitly includes SolidWorks .sldprt versions 1999 through 2026. A single SLDPRT part can be imported by itself; a complete SolidWorks assembly would be a different matter because it can depend on other component files.
The first route is the Documents page: use Import, choose the SLDPRT, and allow Onshape to translate it. Another route is Import from a Part Studio. After processing, open the translated Part Studio and check that the geometry appears in the Parts list as solid bodies, rather than merely as an attached original file. If translation fails, inspect the import status and version rather than converting the file to STL and losing useful surfaces.
To get it into Plasticity, right-click the resulting Part Studio tab or the specific part and choose Export. In the format selector choose STEP; choose a millimeter unit if appropriate, then Download. Onshape’s export help confirms STEP and even offers Parasolid as an alternative. Exporting does not recreate the original SolidWorks feature history, but it preserves usable boundary-representation geometry when translation succeeds.
There is a licensing catch worth checking before using a personal file: Onshape Free documents are public, while private documents require a qualifying plan. A proprietary customer model should not be uploaded to a public workspace without permission. For an ordinary tool reference, this may be acceptable; check document visibility before uploading.
A precise success test is to import, verify a cylindrical housing can be selected as a real face, export STEP, then open that STEP in Plasticity and measure the gripping diameter. That is enough to begin a vise around the real body, without spending time on a mesh reconstruction or an unrelated Dremel model.
Go to Source — https://cad.onshape.com/help/Content/Document/importing_files.htm