The sandpaper component is silicon carbide.

Filing nails is a manicure tool that is mainly used for trimming, shaping and polishing real nails, fake nails, crystal nails or toenails. The main component of sandpaper for filing nails is silicon carbide. Silicon carbide is a man-made material made from quartz sand, wood chips, clay and other materials combined in a furnace. Silicon carbide has the characteristics of high hardness, wear resistance, and high temperature resistance, so it is often used to make abrasive tools such as sandpaper and grinding wheels.