Pearl Abrasive's High Density Zirconia Flap Disc. The Pearl FATMAX High Density Zirconia Flap Disc is excellent on both non-ferrous and ferrous metals including Stainless Steel. The FATMAX comes in Type 27 or Type 29, in both 4-1/2" and 5" diameters, and in grits of 40,60,80, and 120. Call Trans American Products today to try these high density flap discs from Pearl Abrasive.