File Filosophy
Being some Hints regarding the proper Methods of using Files and the various Applications of the most common Files

FILE FILOSOPHY First Use of a File In economizing the wear of files intended for general purposes, consideration should be given to the kind of material to which they may be subjected in the different stages of their use. In the ordinary use of the machine shop, the first wear of these files should be in finishing the larger surfaces of cast iron, bronze or brass metals, all of which require a keen cutting tooth; they may then be made to do good execution upon the narrower surfaces of these metals, and also upon wrought iron and soft steel; as a file that has been used more or less upon this kind of work will not tear the surface of these metals and will consequently do more effective work. To obtain the best results, the file suited for general purposes is not so well adapted to filing brass or other similar soft metals as those whose teeth are arranged for this purpose. New files, particularly double cuts, are severely worn down by use upon narrow surfaces, as the strain comes wholly upon a few teeth and frequently breaks them. Preparing Work The corners or thin edges of iron castings are very likely to become chilled and a thin scale or skin pro- duced over the entire surface of the casting, caused by the hot metal conning in contact with the moist sand of the foundry moulds; this outer skin is usually much harder than the metal beneath it, and many times NIC H OLSON FILE CO. 23