Walnut shell abrasive is used to clean and polish soft metals, fibreglass, wood, plastics and stone. Walnut shell also works as a deburring and deflashing product for mouldings, castings and electrical parts. Walnut shell is very efficient when used to tumble and polish jewellery, metal parts, and to prepare surfaces for painting. Walnut shell is a100% organic product and is non toxic and bio-degradable. Typical 3.0 Mohs.