b'Abrasives require more attention than they often are given.By Christopher Tate and how the application of abra- have been used by humankind for sive products often is not given thethousands of years. Technologi-Asales representativessame considerations as other met- cal advances have resulted in hu-few years ago, one of our local industrialalworking processes. man-made materials, such as sili-was giving his best pitch. He told meMetalworking professionals usecon carbide, synthetic diamond and we should use his brand of coatedabrasives to clean parts, shape ge- aluminum oxide, which is the most abrasives, and I joked that he wasometries, prepare surfaces, im- frequent of these in modern met-trying to sell sandpaper to me. prove appearances, size featuresalworking. Human-made abrasive We sell a million dollars worthand cut parts. Todays metalwork- grains are the most prevalent mate-of sandpaper in a year, he replied,ing would not be possible withoutrial in contemporary manufacturing.so we refer to them as coatedmodern abrasives.abrasives. Abrasivegrainslikepumice,Types of AbrasivesThis lighthearted conversationcalcite, walnut shells and garnet,Abrasive products are manu-made me think about the signifi- which is the most common grainfactured in various forms and pre-cance of abrasives in metalworkingin sandpaper, occur naturally andsented to a workpiece in numerous The grinding attachment for the 200 metric ton (220 ton) lathe at Mitsubishi Hitachi Power Systems Americas uses a large aluminum oxide wheel (left). Welding superalloys requires a lot of cleaning with abrasives to ensure weld quality (right).C. Tate30DECEMBER 2020 Abrasives.indd 30 11/13/20 4:19 PM'