1.1 ,This test method covers the determination of the attrition and abrasion resistance of catalysts and catalyst carriers. It is applicable to tablets, extrudate, spheres, and irregularly shaped particles larger than about ¹/₁₆ ,in. (1.6 mm) and smaller than about ³/₄ ,in. (19 mm). The materials used in developing the method exhibited losses on attrition less than 7 ,%, however, the method should be applicable to materials giving much higher attritions.