25lbs Extra-Fine, 40 grit, .025"; 6.0 - 7.0 MOHS; Fast cutting, economical abrasive used to remove heavy rust scale or paint from steel and other hard materials; Typically used in a pressure blaster or siphon blaster where the abrasive is not being recycled.; Moisture resistant and does not pack which reduces clogging; Has sharp angular edges and provides a high degree of etch for surface preparation- ALC 25# Coal Slag Abrasive/Fine 40093.