Multi-purpose Files. Flat file is used for finishing, shaping and deburring a wide range of materials. Half Round file & Round file are used for sharpening, shaping, removing material and deburring from the inside surfaces of cylindrical workpieces. Wood Rasp file shapes and quickly removes material from Wood, Leather, Soft Metals, and Soft Plastics. Squared file is used for removing material quickly when turning round drill holes into_square_slots and is mostly used in slots and key ways. Triangular file is used for trimming and sharpening edges. Its unique, three-sided design makes it a great tool for sharpening hard-to-reach places such as saw teeth.