CGW-Camel Grinding Wheels' introduces green grind, a high-performance, depressed-center grinding wheel. Manufactured from a premium bond and zirconia-aluminum oxide grain mixture, the wheel coolly grinds metal 50 percent faster than typical aluminum oxide wheels and will not discolor or warp stainless steel, according to the manufacturer. Containing less than 0.1 percent of sulfur, chlorine and iron, green grind wheels can be used for tank fabrication, power plant maintenance and metal fabrication. Comes in 36-grit size, type 27 shape, with 4 1/2-, 5- and 7" diameters with 7/8" or 5/8"-11 arbor hole.