Crescent/Nicholson Flat Double- Smooth Files Ideal for machinists, machinery builders, ship and engine builders. Can be used effectively by repairmen and others who require rapid removal of metal. Rectangular cross-section allows you to smooth and sharpen straight surfaces, while slight taper in width towards the file's point creates ease of access in slots. Double- on the sides for rough filing and single- on the edges for a smooth finish. Pack of 1