Manufactured from premium quality, high grade silicon carbide abrasive grit. Silicon carbide bench grinder wheels are engineered with precision for extensive product life and cool and consistent grinding on a wide range of materials. Designed for use on a bench or pedestal grinder for deburring and sharpening of parts and tools.Vitrified bond for precision grinding. Unaffected by water, acid and oils. All with 31.75mm bore, supplied with 1", 7/8", 3/4", 5/8" and 1/2" bore nylon bushes.All York grinding wheels are supplied in a unique storage box, which helps prevent chipping and other accidental damage. Spare cases available.Type 1: Straight grinding wheels.Note: Truing recommended before first use.