Alc 41100 40 grit coal slag – 50 lbs. 50lbs; 40 grit; .025″ approximate size; 6.0-7.0 mohs; coal slag abrasive is a fast cutting, economical abrasive used to remove heavy rust scale or paint from steel and other hard materials; this abrasive is typically used in a pressure blaster or siphon blaster where the abrasive is not being recycled; coal slag is moisture resistant and does not pack which reduces clogging; this abrasive has sharp angular edges and provides a high degree of etch for surface preparation and coating adhesion