3” 30PCS ALUMINIUM OXIDE SANDING DISCS SET (24/36/60#) Quick-change sanding discs are made with aluminum oxide abrasive grains and feature active grinding aids to prevent loading and reduce heat buildup. The top choice for METAL grinding & WOOD sanding Aluminum oxide grinding discs are the top choice for metal grinding, polishing, and wood sanding. These wedge-shaped particles are exceptionally tough and resistant to breakage, making them excellent for removing metal or heavy wood paint. All sanding cloths are made with a thickened cloth base and feature a high-toughness cotton backing on the back, providing the sanding disc with more elasticity. They are suitable for flat and side sanding and can also enhance the plastic connection on the sanding disc. Perfect for deburring, finishing, and cleaning on various types of surfaces, use them for aggressive sanding and grinding on automotive paint, primers, body fillers, and putties before painting, or for removing scratches on wood and paint. Excellent for taking down any high spots, cleaning off rust/paint or mill scale. As a tip, the pads will last much longer if you add a few spots of engine oil or polishing compound. It keeps the debris from sticking to the pad.