Air-powered grinders and cut-off tools rotate abrasive wheels or other attachments to remove material and prepare surfaces for coating. These tools run on compressed air and are lightweight to minimize operator fatigue during extended use. They contain few moving parts, so they tend to run cool and have a long lifespan. Vertical grinders apply uniform pressure to grinding wheels for aggressive material removal on large, flat surfaces. Angle grinders hold grinding or cut-off wheels at a right angle to the tool body and are more compact, more versatile, and less aggressive than vertical grinders. Straight wheel grinders use thick wheels or stones to perform like handheld bench grinders. Die grinders grind, debur, and polish using burs, mounted points, and other attachments to perform more detailed work than larger grinders. Pencil grinders are even smaller and slimmer than die grinders for extra-fine control. Cut-off tools are dedicated cutting tools that make cleaner cuts than angle grinders.