<P> Files come in a wide variety of materials, sizes, shapes, cuts, and tooth configurations . The cross-section of a file can be flat, round, half - round, triangular, square, knife edge or of a more specialized shape . Steel files are made from high carbon steel (1.0 to 1.25% carbon) and may be through hardened or case hardened . </P> <P> There is no unitary international standard for file nomenclature; however, there are many generally accepted names for certain kinds of files . A file is "blunt" if its sides and width are both parallel throughout its length . It is "tapered" if there is a reduction in its dimensions from its heel toward its point . A file may taper in width, in thickness, or both . A "tang" is a protrusion at the heel, tapered, parallel sided, or conical, for gripping, inserting in a handle, or mounting in a chuck . </P> <P> The cut of the file refers to how fine its teeth are . They are defined as (from roughest to smoothest): rough, middle, bastard, second cut, smooth, and dead smooth . A single - cut file has one set of parallel teeth while a cross-cut or double - cut file has a second set of cuts forming diamond shaped cutting surfaces . In Swiss - pattern files the teeth are cut at a shallower angle, and are graded by number, with a number 1 file being coarser than a number 2, etc . Most files have teeth on all faces, but some specialty flat files have teeth on only one face or one edge, so that the user can come right up to another edge without damaging the finish on it . </P> <P> Some of the common shapes and their uses: </P>

Difference between single cut and double cut files
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