Blade R30 Arc Shaped Finish Blade for Burr-Bi. R30 Arc Shaped Hi-Speed Steel Blade. For finish on materials up to 0.63" (16mm) thick. Use a single R30 for one straight edge, two blades at once to deburr both edges simultaneously. Great for Straight Edge and Sheet Applications. Good for use on Steel, Aluminum, Copper, Stainless Steel, and Plastics