Best used at a 15 to 25 degree angle, the Edge Flap Disc is ideal for finishing fillet welds and other harder to reach joints. The top, bottom, and edges of the disc can all be used for metal grinding. With a 4-1/2 in diameter, the edges are particularly useful for getting into tight spaces and sanding small areas without damaging adjacent material. The type 29 conical wheel shape has a slight angle which is better for aggressive grinding, shaping, and contouring of surfaces, while the premium zirconium oxide grit sandpaper creates a consistent, smooth surface finish.