Norton Gemini Type 28 saucer depressed center wheels have durable, versatile aluminum oxide for weld grinding, metal fabrication, and in a variety of other metalworking applications, from the inside the foundry to building a ship. Depressed center wheels are shaped to prevent gouging of the workpiece.

Reinforced wheels are designed to resist breakage caused by severe cross-bending and are required on any operation where the work is not securely clamped. Resin bonds are organic bonds that soften under the heat of grinding, releasing dulled abrasive grains. Because of its forgiving nature, only an organic type bond is used in cutoff wheels. The resin-bonded wheel is more resilient than a vitrified wheel. The manufacturing term for a resin bond wheel is "cured," meaning the wheel has been heated to less than 500 degrees F. Depressed center wheels with saucer-shaped grinding faces have inset centers and curved faces are used for cutting off and portable grinding. The depressed center prevents the tool mandrel from gouging the workpiece. These wheels are typically used on convex workpieces at a slight angle with the workpiece. Depressed center wheels are frequently used with right-angle grinders. Using a harder grade wheel increases wheel life but also increases burn and requires more power, and decreases cut rate. Burn is the effect on a workpiece from thermal stress as abrasive cuts or rubs material away. The damage ranges from discoloration to cracking of the workpiece.

Aluminum oxide is a widely used and versatile abrasive material. It is a tough, fracture- and wear-resistant grit that works well with a broad range of materials, from metals to wood. Aluminum oxide is more durable than silicon carbide and often used for material removal and finishing.

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, grinding, 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.