1-1/2" COMBIDISC RS Abrasive Disc - Type CDR - Silicon Carbide - 120 Grit, PK 100 RS type COMBIDISC abrasive discs are outstandingly well suited for weld dressing of backwardsrepair welds, e.For universal grinding work on components made from aluminium, copper, bronze, titanium and fibre-reinforced plastics.. Recommended for use on titanium alloys.