Norton Twinfiber type 29, abrasive flap discs offer the most aggressive stock removal for mild steel, and ferrous metals. Norton flap discs are designed for right-angle, handheld, grinding machines for stock removal and surface blending.
With a type 29 flap disc, hold the grinder in operation at an angle between fifteen and twenty five degrees to the work surface. Steeper angles will weaken the flap edges. The weight of the backing is designated by letters J, X, Y, T or M. J is the lightest and M is the heaviest. A more flexible backing will follow irregular contours of a workpiece better than a stiffer one. Stiffer backing is more suited for regular round or flat surfaces.
Coated abrasives have individual abrasive grains spaced at a predetermined distance from one another. This is a closed-coat disc. A closed coat covers 100 percent of the surface with abrasive grains, for more stiffness and better surface finish than an equivalent open coat, where abrasive grit covers 50 to 70 percent of the surface. This disc features a resin bond. Resin bonds have good moisture resistance, are harder and less flexible than glue bonds, and have good heat resistance and grain retention. Resin bonds are useful for abrasive operations with high operating speeds, impact, and sudden loading, as the resin bond is strong and can withstand rough treatment. Use with molded rubber back-up pads, using a hard pad for aggressive cutting, a medium pad for general purpose applications, or a soft pad for contours and fine finishing work.
Ceramic and zirconia alumina blend is tougher than aluminum oxide, and is self-sharpening. It is formed in a process where alumina gel is dried and then crushed. These engineered crystals fracture and refracture at fine levels, to form a smooth, self-sharpening abrasive material. This blend has excellent performance and efficiencies on mild carbon steel, ferrous metal, cast iron applications. It offers three times the working life of aluminum oxide.
Abrasives are used for a variety of applications from shaping a part to fine finishing, depending on the grit size. Low grit numbers like 40 are coarse and are used for removing excess material and shaping a part. High grit numbers like 400 are fine and help to create a smooth surface finish.
Norton Abrasives manufactures a wide variety of sanding, sanding, and polishing abrasives, and has been located in the United States since 1885. In 1990, Saint-Gobain purchased Norton, keeping its manufacturing facilities and offices in the same location. Norton/Saint-Gobain has been recognized as a Global 100 Sustainable Company, as well as earning ISO 9000 and 14001 certification for quality and environmental management standards.