Here's what I suggest
Using the Content Center editor... Edit this washer's family table and add a row (copying/pasting the existing one) and define your material you need for that instance. Then you will need to add the material column as a key column so the material field will appear in the place from content center dialog. You will also need to change file name structure as well so it incorporates the material info in it.
Then you can do a change size function and select the replace all option.
Just another option... 
Mark Lancaster
& Autodesk Services MarketPlace Provider
Autodesk Inventor Certified Professional & not an Autodesk Employee
Likes is much appreciated if the information I have shared is helpful to you and/or others
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