Hardness

One way of identifying whether abrasives are suitable for a specific cleaning process is to look at their relative hardness according too the Rockwell scale for metallic abrasives and the Mohs’ scale for non metallic abrasives. Table 1 lists the relative hardness of various abrasives discussed in this article. The larger size of the hardness range for the metallic abrasives reflects the fact that they can be heat treated after casting to change their hardness.