18 Inch No Hole Abrasive Sanding Discs. Aluminum Oxide Metalworking Aluminum Oxide. Closed coat, Heavy X weight Ploy Cloth backing. Sold individually. High quality and long lasting industrial abrasive Aluminum Oxide Metalworking sanding Discs work great on automotive applications, non ferrous Aluminum Oxide Metals (Aluminum, Copper, Titanium, Nickel). Heavy duty X-wgt material provides extra strength for working with Aluminum Oxide Metal. Quality stick on PSA backing with release paper to protect adhesive from contaminants allowing for superior grip. Resin over resin bonding. Anti-clogging stearate (provides a better sanding and cleaner working environment). Wet or Dry applications. Assembled in America.