What Are Grinding Discs

Grinding wheels and discs aggressively and quickly shape and remove metal and are ideal to use when the finish doesn’t matter. Common uses include smoothing weld beads, removing rust, grinding edges and rapidly removing stock. They are often used in fabrication, trailer/equipment repair and general maintenance.

Grinding wheels are bonded abrasives designed to be more aggressive than coated abrasives. They are typically used on right angle grinders and held at a 15-degree angle against the work piece instead of perpendicular. This allows you to have greater control of the tool. Most grinding wheels have depressed centers, which keeps the wheel mounting nut away from the work surface.

When it comes to grinding discs, there are two common styles:

  • Type 27 wheels are flat across the bottom to allow for aggressive grinding on flat surfaces.
  • Type 29 wheels have a 30-degree angle around the outside that allows for grinding irregular and contoured surfaces.

They are available in multiple diameters, but the 4-inch and 4½-inch are the most popular. The diameter you need depends on the grinding tool you’re using.