Flexible Diamond Expanding Sanding Belts For customers who grind and smooth materials using silicon carbide or diamond grit, the expanding rubber drums is an excellent wheel and the flexible diamond expanding drum sanding belt is suitable for inflatable rubber barrels for wet or dry grinding, polishing, Deformed glass and ceramic to achieve consistent surface finish long service life. Our flexible diamond drum belt are ideal for wet grinding of various materials, including stone, glass, ceramic, lapidary and other hard materials, and are ideal for forming and polishing internal cuts and flat edges with hand-held or stationary machines.