3M™ Fibre Disc 581C Blue. The 3M™ 581C fibre disc features high-performance Zironia aluminium abrasive grain that's on a fibre backing. The abrasive is resin bonded and close coated that offers great performance and a consistent quality finish. Suitable for a variety of general purpose metalworking applications from deburring and finishing. Outstanding Cutting Performance. The 581C disc contains an impressive Zirona aluminium abrasive blend on fibre backed disc giving a great performance on an angle grinder. The disc is suitable for use on a range of metals from grinding and finishing weld seams on most metals. Features and Benefits. Good performance with consistent quality finish Alumina-zirconia abrasive on a fibre backing that ‘s closed-coated and resin bonded Ideal for grinding and finishing weld seams on all metals. For use with a 3M™ Right Angle Grinder, compatible with 3M faceplates: 115 mm - ; 337-3929 337-3929 , 127 mm - ; 387-4220 387-4220. Typical Applications. These fibre discs are great for weld removals, grinding and blending large and small metal areas. This could occur in industries such as farm and construction, automotive, ship and boat building, metal fabrication. FAQ's. Would you be able to use these discs on wood . No, these are not recommended to be used on wood, just metals.