Unofficial browser extension to streamline adding McMaster files to your Onshape workspace (currently Chrome only)
Recreates the convenience of the SOLIDWORKS McMaster-Carr plugin for Onshape. A Chrome extension adds a sidepanel with a "Send to Onshape" button that lets you browse www.mcmaster.com and upload STEP files straight to your Onshape workspace.
- Open: Click on the extension to open the side panel.
- Browse: Find a part on McMaster-Carr and select 3-D STEP from the CAD format dropdown.
- Click: Hit the blue "🚀 Send to Onshape (Document Name)" button.
- Done: The file uploads directly to your open Onshape workspace. The translated part studio tab appears within a few seconds.
https://chromewebstore.google.com/detail/mcmaster-to-onshape/gccddcjlidkaikbodlchikmhjidodgcp
- Open Chrome and go to
chrome://extensions/ - Enable Developer mode (toggle in the top-right corner)
- Click Load unpacked
- Select the
chromefolder - Follow the instructions in the popup. They can be accessed at any time by right clicking on the icon and selecting "options"
- Open your Onshape document in a Chrome tab
- Click on the Extension to bring up the sidebar
- Go to McMaster-Carr and find a part
- Select 3-D STEP from the CAD format dropdown (on a product page or category preview)
- Click 🚀 Send to Onshape — the button shows the target document name in parentheses
- Switch to Onshape — the new part studio tab appears within a few seconds
Advanced usage - if you have multiple tabs, copy/paste your onshape URL to the Options page. Works on both individual product pages and category pages (the inline part preview panel).
API keys are stored locally in your browser via chrome.storage.sync. They are never sent to any server other than cad.onshape.com directly. See the privacy policy for full details.
| Problem | Fix |
|---|---|
| Button doesn't turn blue | Make sure the 3-D STEP CAD dropdown is visible on the page |
| Button doesn't turn blue | Try refreshing McMaster |
| "No Onshape document tab found" | Open an Onshape document in another tab, or set a hardcoded URL in Options |
| Wrong document targeted | Set the target document URL explicitly in Options |
| Part name shows as category slug | Ensure the STEP download link is visible — the extension reads the filename from it |
| API error on upload | Double-check your API keys in Options; make sure both read and write permissions are checked |