Assuming a notional 4.5" disc, on a common 4.5" angle grinder:
Which abrasive cuts faster, a flap disc, a sanding disc or a grinding wheel of common grit (I believe 36 or 40)?
Assume, at least for the sanding disc, and the flap disc that the abrasive material are similar, for example, aluminum oxide. Ditto for the grinding disc, however they do not seem to be as clearly marked as to the abrasive material.