Length 140mm, set of 5 pieces. File shapes include flat, round, half-round, triangular, and square. Can be used on glass, tile, metal, gemstones, for mold making, die-making, and more. Diamond files cut in all directions and produce a better finish. They can also work sideways and with a twisting motion. Widely used on alloy steel, tungsten carbide, glass, tool steel, semi-precious stones, hard stones, die moulds, saw blades, cutting tools, carbide inserts, and anywhere hard grinding and sharpening is required.