Diamond files and sheets are used for tasks where conventional files fail due to the hardness of the material being worked on. Diamond files and sheets are also used for processing hardened steel. The working temperatures are so low that no chemical wear occurs. This allows the higher hardness of the diamond grain to be exploited for a longer tool life. The conical diamond files are used in tool-making for particularly narrow, deep-set contours. The forged shank allows for use without an additional handle.