Is the file extension for a SolidWorks part always .SLDPRT?

ByCADbrief Staff

Short Answer

Yes — in standard SolidWorks workflows, a native solidworks part file normally uses the Save As output with the .SLDPRT extension. That is the default and most common professional format for single-part models. Limitation: imported or neutral-format files are not always saved as .SLDPRT until you resave them in SolidWorks.

What You Need to Know Before

Warning: A file can look like a SolidWorks part in Windows Explorer even when it is actually an imported STEP, IGES, or Parasolid model not yet fully converted into a native SolidWorks feature-based file. This often causes missing feature history, broken references, or limited editability after opening.

How to Check or Save the Correct SolidWorks Part Extension

  • Command: Save As

  • Shortcut: F12

  • Quick Steps:

    1. Open the part file in SolidWorks, then go to File > Save As.
    2. In the Save as type dropdown, verify that *Part (.sldprt)** is selected.
    3. Click Save, and if needed enable the relevant options for the current file format before confirming.

Variables & Settings

  • Key Setting: Save as type

    This option controls whether the file is saved as a native SolidWorks part (.SLDPRT) or as another format such as STEP, IGES, or Parasolid. In professional workflows, always confirm this dropdown before issuing files to manufacturing, PDM, or downstream CAD users.

Why it Fails

  • Cause 1 (Geometry): The model was opened from a neutral format like STEP or IGES, so it may behave like a part in SolidWorks but is not yet stored as a native .SLDPRT file.

  • Cause 2 (layers/Locks): PDM status, read-only permissions, or vault-controlled file naming can prevent resaving the file with the expected .SLDPRT extension.

  • Cause 3 (Command/Logic): The user selects a different Save as type format, such as .STEP or .X_T, so the exported file is no longer a native SolidWorks part file.

Quick Fix & Best Practice

  • Quick Fix: Use File > Save As and explicitly set *Save as type = Part (.sldprt)** before saving.
  • Manager’s Verdict: Use .SLDPRT for all editable native SolidWorks part deliverables; use neutral formats only for exchange, vendor sharing, or software interoperability.

FAQ

Can a STEP file be a SolidWorks part?
It can open as a part document, but it is not a native .SLDPRT file until saved as one.

Are all SolidWorks 3D files .SLDPRT?
No, assemblies use .SLDASM and drawings use .SLDDRW.

Can I rename another file extension to .SLDPRT manually?
No, changing the extension alone does not convert the file into a valid native SolidWorks part.

.

Related Posts: