Precision-shaped ceramic alumina discs abrade hard metals like stainless steel faster than standard ceramic alumina discs because of their sharp, outwardly pointed grit. The grain particles continually fracture to produce new, sharp cutting edges while maintaining their specially engineered points and angle. The design also reduces heat generation while sanding, which prevents the grit from wearing down. These discs are also good for sanding steel and soft metals, and a stiff fiber backing provides support for heavy material removal. Fit these discs over your tool’s arbor. They require a backup pad (sold separately). Discs with threaded arbor hole don’t need a nut to secure, enabling quick disc changes.