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Few tools can lay claim to as great
antiquity as the file.
So very old is it, indeed, that no mention can
be found in either profane or sacred history of its inventor or
the d ate of its invention, for it antedates written history; but
in
the Bible, in second Samuel, the thirteenth chapter and the
twenty first verse, is to be found the following: "Yet they had
a file for the mattocks, and for the colters, and for the forks,
and for the axes, and to sharpen the goads."
This was 1098 years before the advent of the
Christian era, and there is every reason to believe that the
file was in use before this time. Certain it is that from that
time on, there are numerous proofs to show that the file became
more and more in general use as the years went on.
In the sixteenth century it had become so common
that all reference to it was in a purely matter-of-fact way, as
when Burnett, in his “History of the Reformation," describing
how Sir Edward Grimston escaped from prison, thought it only
necessary to say that the cell bars were cut apart with a file.
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It has only been within the past quarter of a
century that there have been placed in operation any marked
improvements in the process of manufacturing files, and even yet
there are many mechanics who still insist that files made by the
methods of a century ago are superior to those made by the more
modern methods of machinery.
Up to within late years this opinion has had all
points of fact in its favor, and even now it may have some.
A
description of the two processes - that is, hand and machinery,
will, therefore, be of interest. Take the former, or hand process, to begin with.
The steel is first rolled, or tilted, into bars
of a size as nearly as possible to the sections required.
The sections bring the steel in the rough, which are cut from
the bar into about the length and diameter the file required.
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Leonardo da Vinci
Scribners Monthly, 1879 |
They are then annealed with great care by
placing them in annealing ovens heated by charcoal, coke or
anthracite coal, until they are of a cherry red, and then
allowed to cool gradually. This sufficiently softens them for
the chisel cutting, but very frequently after being taken out of
the oven it is found that the heat has bent or warped them. Should this be the case, they are forged into shape again.
They are now filed or ground, the grinding being done on a huge
stone, six feet in diameter, the workman sitting almost astride
of it and holding the steel directly on the stone with both
hands. In olden times, and even in years not long past, this was
a dangerous process, as the stone would sometimes break while in
motion, with fatal results to the workman. These accidents are
rare in this country, owing both to the care exercised by the
grinders and the superiority of the stone used.
After the blanks are ground, they are "stripped"
- that is, they are filed down to a true surface to remove all
irregularities.
They are now ready for the cutter, who sits
astride a bench in front of the block or anvil, across which
rests the file. It is held firmly in place by a strap across
either end, into the lower loops of which are placed the
cutter's feet, like stirrups, the weight of the legs thus firmly
holding the bar in place.

The tang (the part to be inserted into the
handle) points towards him, and, after slightly greasing the
"blank," he is ready to cut the teeth.
In his left hand he holds
a small chisel, the edge of which always exceeds the width of
the file, and placing it on the '' blank," with an inclination
of from 40° to 55°, according to the character of the file to be
made, he gives it a sharp blow with the hammer in his right
hand.
An indentation in the farthest or small end of
the file is thus made, the indentation naturally inclining
towards him. This, of course, leaves a ridge, or a tooth,
slightly thrown up above the surface, and, following this as a
guide, he places his chisel alongside of it and strikes another
blow with his hammer.
This is continued until the teeth are
cut the full length of the face of the blank. An average workman
will strike from sixty to eighty of these blows per minute.
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