Premium aluminum oxide with grinding aid for grinding and finishing on stainless steel with minimal discoloration.Works great on aluminum and non-ferrous materials with minimal loading.Provides long life while maintaining high stock removal rates.Trimmable design allows for easy trimming to expose more material.Type 27., Only the TrimBack?âòÀÞ?â line of flap discs are able to be trimmed to expose more abrasive overhang.Never trim beyond the maximum trim line (more than 1/4") or the ridged edge of the backing TrimBack?âòÀÞ?â plastic backing.Always mount a TrimBack?âòÀÞ?â flap disc on a properly guarded right angle grinder.To properly trim a TrimBack?âòÀÞ?â flap disc, apply the plastic backing to a secured metal workpiece while the grinder is running.TrimBack?âòÀÞ?â Stainless is also available in a Type 29 Shape.