File Cutting. File Cutting.
The cutting of the teeth is usually performed by workmen sitting astride upon a board or saddle-shaped seat in front of a bench, upon which is fixed a kind of small anvil. Laying the blank file across the anvil, the Cutler secures it from moving by a strap which passes over each end and under his feet, like the stirrup of the shoemaker. He then takes in his left hand a very carefully ground chisel made of the best steel, and in his right a peculiarly shaped hammer. If the file be flat, or have one or more flat surfaces, the operator places the steel chisel upon it at a particular angle or inclination, and with one blow of the hammer cuts an indentation or furrow completely across its face from side to side, and then moves the chisel to the requisite positions for making similar and parallel cuts. If it be a half round file, as a straight-edged chisel is used, a number of small cuts are necessary to extend across the file from edge to edge. So minute are these cuts in some kinds of files, that in one specimen about ten inches long, flat on one side and round on the other, there are more than 20,000 cuts, each made with a separate blow from the hammer, and the cutting tool being shifted after each blow. The range of manufactures afford few more striking examples of the peculiar manual skill acquired by long practice.
Several highly ingenious machines have been contrived for superseding the tedious operation of file cutting by hand; but suited as the process may appear to be for the use of machinery, it has been found to present such great difficulties, that we believe no file-cutting engine has been brought successfully or extensively into operation. One very serious difficulty arises from the fact that, if one part of the file be either a little softer than the adjacent parts, or a little narrower, so as to present less resistance to the blow of the hammer, a machine would, owing to the perfect uniformity of its stroke, make a deeper cut there than elsewhere.
After the files have been cut, the steel is brought to a state of great hardness; this is effected in various ways, according to the purpose to which the file is to be applied; they are generally coated with a sort of temporary varnish, then heated in a stove, and then suddenly quenched. After hardening, the files are scoured, washed, dried, and tested.
It will be seen that the tools employed by the Cutler are few, and consist mostly of the hammers, moulds, dies, anvils, grinding stones, and others already mentioned.
COTTON MANUFACTURER.
