Extract from A MONTH IN YORKSHIRE.
No reference to Birmingham but gives an idea of how the metal must be prepared. Benjamin Sheldon in Legge Street 'made' some of his metal (though not when his sons joined him) but there must have been a range of small masters making specialist metals for tooling and guns on a larger scale
A MONTH IN YORKSHIRE.
Walter White 1861
From the razors I went to the files, at Moss and Gamble's
manufactory, in another part of the town. My first impression of the file-works, combined stacks of
Swedish iron in bars; ranges of steel bars of various shape,
square, flat, three-cornered, round, and half-round; heaps of
broken steel, the fresh edges glittering in the sun; heaps of
broken crucibles, and the roar of furnaces, noise of bellows,
hammer-strokes innumerable, and dust and smoke, and other
things, that to a stranger had very much the appearance of
rubbish and confusion.
However, there is no confusion; every man is diligent at
his task; so if you please, reader, we will try and get a
notion of the way in which those bars of Swedish iron are
converted into excellent files. Swedish iron is chosen because
it is the best; no iron hitherto discovered equals it for purity •
and strength, and of this the most esteemed is known as '
Hoop L,' from its brand being an L within a hoop. "If
you want good steel to come out of the furnace," say the
knowing ones, "you must put good iron in;" and some of
them hold that, "when the devil is put into the crucible,
nothing but the devil will come out:" hence we may believe
their moral code to be sufficient for its purpose. The bars, at
a guess, are about eight feet long, three inches broad, and one
inch thick. To begin the process, they are piled in a furnace
between alternate layers of charcoal, the surfaces kept carefully
from contact, and are there subjected to fire for eight or
nine days. To enable the workmen to watch the process,
small trial pieces are so placed that they can be drawn out for
examination through a small hole in the front of the furnace.
In large furnaces, twelve tons of iron are converted at once.
The long-continued heat, which is kept below the melting-
point, drives off the impurities; the bars, from contact with the
charcoal, become carbonized and hardevi"d; and when the fiery
ordeal is over, they appear thickly bossed with bubbles or blisters,
in which condition they are described as ' blistered steel.'
Now come the operations which convert these blistered bars
into the finished bars of steel above-mentioned, smooth and
uniform of surface, and well-nigh hard as diamond. The
blistered bars are taken from the furnace and broken up into
small pieces; the fresh edges show innumerable crystals of
different dimensions, according to the quality of the iron, and
have much the appearance of frosted silver. The pieces are
carefully assorted and weighed. The weighers judge of the
quality at a glance, and mix the sorts in due proportion in the
scales in readiness for the melters, who put each parcel into
its proper crucible, and drop the crucibles through holes in a
floor into a glowing furnace, where they are left for about
half a day.
The making of the crucibles is a much more important part
of the operation than would be imagined. They must be of
uniform dimensions and quality, or the steel is deteriorated,
and they fail in the fire. They are made on the premises, for
every melting requires new crucibles. In an underground
chamber I saw men at work, treading a large flat heap of
fire-clay into proper consistency, weighing it into lumps of a
given weight; placing these lumps one after the other in a
circular mould, and driving in upon them, with a ponderous
mallet, a circular block of the same form and height as the
mould, but smaller. As the block sinks under the heavy
blows, the clay is forced against the sides of the mould ; and
when the block can descend no further, there appears all
round it a dense ring of clay, and the mould is full. Now,
with a dexterous turn, the block is drawn out; the crucible is
separated from the mould, and shows itself as a smooth vase,
nearly two feet in height. The mouth is carefully finished,
and a lid of the same clay fitted, and the crucible is ready for
its further treatment. When placed in the furnace, the lids
are sealed on with soft clay. The man who treads the clay
needs a good stock of patience, for lumps, however small, are
fatal to the crucibles.
When the moment arrived, I was summoned to witness the
casting. The men had tied round their shins pieces of old
sacking, as protection from the heat; they opened the holes
in the floor, knocked off the lid of the crucible, and two of
them, each with tongs, lifted the crucible from the intensely
heated furnace. How it quivered, and glowed, and threw off
sparks, and diffused around a scorching temperature! It
amazed me that the men could bear it. When two crucibles
are lifted out, they are emptied at the same time into the
mould; not hap-hazard, but with care that the streams shall
unite, and not touch the sides of the mould as they fall.
Neglect of this precaution injures the quality. Another precaution
is to shut out cold draughts of air during the casting.
To judge by the ear, you would fancy the men were pouring
out gallons of cream.
The contents of two crucibles form an ingot, short, thick,
and heavy. I saw a number of such ingots in the yard. The
next process is to heat them, and to pass them while hot
between the rollers which convert them into bars of any
required form. I was content to forego a visit to the rolling-
mill—somewhere in the suburbs—being already familiar with
the operation of rolling iron.
We have now the steel in a form ready for the file-makers.
Two forgers, one of whom wields a heavy two-handed ham-mer, cut the bars into lengths, and after a few minutes of fire
and anvil, the future file is formed, one end at a time, from
tang to point, and stamped. For the half-round files, a suitable
depression is made at one side of the anvil. Then comes
a softening process to prepare the files for the men who grind
or file them to a true form, and for toothing. To cut the
teeth, the man or boy lays the file on a proper bed, takes a
short, hard chisel between the thumb and finger of his left
hand, holds it leaning from him at the required angle, and
strikes a blow with the hammer. The blow produces a nick
with a slight ridge by its side; against this ridge the chisel
is placed for the next stroke, and so on to the next, until, by
multiplied blows, the file is fully toothed. The process takes
long to describe, but is, in reality, expeditious, as testified by
the rapid clatter. Some of the largest files require two men —
one to hold the chisel, the other to strike. For the teeth of
rasps, a pyramidal punch is used. The different kinds of files
are described as roughs, ....... cut, second cut, smooth, and
dead smooth; besides an extraordinary heavy sort, known as
rubbers. According to the cut, so is the weight of the hammer
employed. Many attempts have been made to cut files
by machinery; but they have all failed. There is something
in the varying touch of human fingers imparting a keenness
to the bite of the file, which the machine with its precise
movements cannot produce—even as thistle spines excel all
metallic contrivances for the dressing of cloth. And very
fortunate it is that machinery can't do everything.
After the toothing, follows the hardening. The hardener
lays a few files in a fire of cinders; blows the bellows till a
cherry-red heat is produced; then he thrusts the file into a
stratum of charcoal, and from that plunges it into a large bath
of cold water, the cleaner and colder the better. The plunge
is not made anyhow, but in a given direction, and with a
varying movement from side to side, according to the shape of
the file. The metal, as it enters the water, and for some
seconds afterwards, frets and moans piteously; and I expected
to see it fly to pieces with the sudden shock. But good steel
is true; the man draws the file out, squints along its edge,
and if he sees it too much warped, gives it a strain upon a
fulcrum, sprinkling it at the same time with cold water. He
then lays it aside, takes another from the fire, and treats it in
a similar way. The hardened files are next scrubbed with sand, are dried,
the tangs are dipped into molten lead to deprive them of their
brittleness; the flies are rubbed over with oil, and scratched
with a harder piece of metal to test their quality—that is, an
attempt is made to scratch them. If the files be good, it
ought to fail. They are then taken between the thumb and
finger, and rung to test their soundness; and if no treacherous
crack betray its presence, they are tied up in parcels for sale.
