The Blue Spot 115mm (4.5") Medium Non Woven Flap Discs are specially designed to be used with angle grinders for cleaning, polishing, deburring and finishing. Ideal for us on various types of metal such as stainless steel, sheet metal, mild steel and high grade steel. Excellent for corners and profiles that require a more flexible abrasive. Best used at a wider angle of 15 to 25 degrees. Type 29. Diameter: 115mm (4 1/2") / Bore: 22.23mm. Maximum safe speed: 13280 RPM (80m/s).