The Sait 3A Fiber Disc has a premium Zirconium grain with grinding aid. The special grain reduces heat build up and loading. The closed coat structure produces more material removal for quick and easy finishing. The disc is ideal for use on stainless steel, high tensile steel, titanium, aluminum and ferrous metals. The vulcanized fiber backing provides easy heavy duty sanding. The Sait-Lok quick change hub extends the disc life, requiring fewer disc changes. Includes 150 discs.