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Learn Mechanical Engineering at Home Series – (Special Types of Files)

written by: Ricky • edited by: Lamar Stonecypher • updated: 10/21/2008

Have you ever wondered what mechanical engineering is all about? I cannot make you a certified mechanical engineer but certainly you can learn a lot about mechanical engineering by reading this Learn from Home series on mechanical engineering.

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    In the last article we studied about the various types of files. In this article we will continue the discussion about the files and know about some special types of files which are not used as commonly as the files mentioned previously, yet are important for a workshop.

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    Special Files

    Cotter File

    A cotter file is nearly same as that of a normal flat file with the only difference being in the cross-section of the shank or blade is not rectangular but rounded off. As the name suggests such files are mainly used to file slots for cotters. Apart from cotters it can also be used for filing plain flat surfaces of small works. Also it has double cut teeth as shown in the diagram.

    Cotter File 

    Cross Cut File

    This file is also similar to a flat file and has single cut teeth while the handle is usually integrated with the shank itself and not a separate part made of wood while the sides slowly taper. The main function of these types of files is to sharpen the worn out teeth of machineries such as those used in agriculture such as reapers, harvesters and so forth.

    Knife Edge File

    The shape of this type of file resembles very closely to an old fashioned bread knife and hence the name knife edged file. This can be seen clearly in the accompanying figure. The teeth on the sides are double cut while the edge has single cut teeth. The main use of this type of file is to file angular shaped recesses or corners and these files typically come in rough cut, second cut and smooth cut types.

    Knife Edge File 

    Needle Files

    These files are very small sized and hardly fit into the same scenario as the previously discussed files which are normally heavy duty. These files are very delicate and used for light class of jobs such as stencil cutting and so forth. Being brittle in nature they require careful handling and avoidance of any excess pressure which might break them. Typically these files range from 3 inches to 8 inches in size having various shapes of the shank such as round, semi-round, square and so forth. Because of their small size they do not have a separate handle but only an integrated handle which is round in shape.

    Having learnt about so many different types of files and their uses, it is also important that we spend some time in learning the basic operation of filing. We will take this up in the next article and learn how to carry out proper filing operation on a workpiece.