All weiler wheels are resin bond formulated for fast, high quality grinding and cutting, and are reinforced with fiberglass webbing to provide stability. Weiler"s type 27 wheels contain no fillers and are made with 100 percentage abrasive grain to maximize cut rate. Fast cut - ideal for use on hard welds and steel, stainless steel, and in low. Pressure, large contact grinding where the harder wheel grade (R) dulls or glazes.