Norton Gemini aluminum oxide bench and pedestal wheels are an economical choice for small job shops and numerous general purpose applications. Aluminum oxide for high speed tool steels and other metals. Aluminum oxide bench and pedestal wheels for steel applications. Arbor bushings to 1 1-1/4 . Specification: very coarse 24. All bench and pedestal wheels must be dressed to prevent loading. Loading can cause excessive heat damage to the workpiece and wheel breakage. Dressing exposes new cutting edges and provides chip clearance. Do not grind wood plastic or any other non-metallic material on a bench or pedestal grinder. Unsecured machines can move causing grinding breakage and injury. Fixed-base bench and pedestal grinders must be secured.