Black corundum is suitable for processing steel, used for glass sandblasting, hardware forging building floors. Among common abrasives, the hardness of brown corundum is slightly lower. However, in the grinding process, the anti-crushing function of its abrasive grains is good, which is suitable for grinding metals with high tensile strength, such as rough grinding and heavy grinding of ordinary steel, especially suitable for carbon steel, general alloy steel, and also for grinding of forged iron and hard bronze