West Virginia argus. [volume] (Kingwood, W. Va.) 1877-1946, 1891-07-23
TgMPERlNo STEEL.
raie yellow for Razors aud Dark Blue
for sawa tho Proper Colorn.

Pale yellow for Razors aud Dark Blue
for sRws the Proper colors.
Steel has been defined as any kind Of
Iron which when heated 20 redness and
suddenly plunged into cold water be-
comes hard; and every kind of mallea-
bic or flexible iron that can be hardened
10y that process is steel. But this def
milton is not applicable TO the steel Of
mild quality now made for many me-
chanical uses, says the Mechanical
News Ono OF tho requisites for this
mild steel is that IL viii not harden after
being heated TO cherry rcd and
plunged into water. TO include all the
kinds OF steel now used In the af,ri-
cultural and mechanical industries, the
better definition OF steel will be, n NAL.
leable iron combined with percentage
OF carbon Chemically considered, steel
occupies n halfway position between
wrought and cast iron, wrought iron
being simply iron almost entirely free
from carbon, while steel that Is 20
be tempered contains one 10 one and
one-half per cent. OF carbon.
Tho reason why this very slight
change In tho chemical construction
should produce such wonderful results
yet an unsolvcd mystery. We know
that bar of iron converted into steel
becomes more granular or open, and
while 1T loses to some extent its tough
ness, II gains, instead, elasticity. great
er strength and closencss of fiber.
Blister steel Is made by heating bars
OF iron packed in charcoal in a furnace
for period Of from six to ten DAYS.
When the metal Is withdrawn the bars
are found to be of crystalline texture,
and have blistered surface-hcnce the
name. Cast steel was formerly made of
blister steel broken into fragments.
melted In crucibles and cast into ingots;
but the modern practice Is To charge
the crreibles with pieces of good Swed-
ish or American bar iron. adding char.
coal and black oxide of manganese.
The heat of the furnace soon seals the
lid OF the crucible, and the melting iron
absorbs carbon from the fumes of the
charcoal, thus shortening the tedious
process OF making blister" bar. The
cast steel is rolled or hammered from
the ingot to any desired bar, sheet or
plate.
The chief characteristic Of steel con.
sists in its capability of being hardened
and tempered, and when exposed to
heat it takes on in succession the fol.
lowing colors:
l. a faint yellow, which indicates n
proper temper for lancets or small cut,
ters that require the finest edge, with
but little strength Of metal.
2. a pale yellow. which indicates the
temper for razors and surgical instru-
ments.
3 Full yellow, for penknives, etc.
with increased toughness.
4. Brown, with purple spots-that be.
ing for axes and carpenters tools.
.. Bright blue, for swords and watch.
springs.
9, Full blue, for fine saws. dasgers
etc.
z. Dark blue, for large saws or In.
struments that may be sharpeued with
a file.
The above colors are based on steel
suitable for the requirements. A piece
OF steel suitable for razors, lancets
etc, would not take the color indicated
for large saws, rs that quality OF steel
is but little above the "blistcr" quality
The finer steel is the less heat IL will
temper at, requiring n lower color q
temper. Recently there have been some
valuable discoveries I'm tcmpering. weld.
ing and restoring steel, both from burnt
or n low qrade