Hand files are used for stock removal, deburring, sharpening, and finishing on metal, wood, and plastic. Files have a pattern type of either American or Swiss, with American files used for more aggressive work and Swiss files used for finer finishing. Common hand file abrasive materials include silicon carbide, steel, CBN, and diamond. Choose a file grade of very coarse to ultrafine depending on the level of precision required. Precision can also be defined by grit, measured in microns.