The morning news. [volume] (Savannah, Ga.) 1887-1900, 1894-12-30
A TALK ABOUT saws.
How They Are Made. Tempered and Put
Upon the Market.

From the Chicago Record.
DIT. Conan Doyle in his interesting tale
Of Micah Clarke" tells of OLD Ironside
Joe's sword. which cut through a helmet
Of proof steel" without turning its edge.
Sir Walter Scott relates marvellous Stories
of the terrible sword of Richard the Lion
Hearted. which could cleave a two-inch
bar of iron when welded by King Richard.
Legends of the wonderful temper strength
and elasticity of the Toledo and Damas-
Gus blades figure extensively in the historl-
cal novels which relate to the romantic
days Of the Templars and Saracens.
Some Of those swords of the middle ages
and the crusades are still in the museums
of Europe, and the modern steeimakers
who have examined them with profess
sional criticism, while admiring their
beautiful workmanship and exquisite art
unhesitaungly say that none of them can
compare with the steel made to-day.
An American manufacturer of tool steel
declared that an American handsaw was
made of stronger, tougher and better
steel than famous Toledo blade exhibited
in France. He proved his assertion, for
sword made of the same steel from which
the saw was made stood the tests to which
both swords were subjected, and then cut
the Toledo blade in two without nicking
the edge of the American sword.
4 good handsaw must of necessity be
made of good steel Its temper must be
such that the thin saw-blade must spring
in an even curve from point TO butt when
il is bent. It must be elastic without be
ing brittle. tough without softness and
the steel must be Of an even temper. From
good, honest steel alone can such virtues
spring, and when n carpenter has such
saw, polished TO silver luster. rightly
hung" well set" with the handle prop
erly fitted to his hand, he has a treasure.
Steal a carpenters chisel. his twO-fOot
rule his spirit level his square, or his
hammer and he will growl and grumble
buy others and go ahead, with his work
Steal his favorite rip-saw and he will lay
on a day to find the thief. Spend another
day to select another saw and for month
after will complain because of his great
loss.
Manufacturers sending out brittle, soft
or poor saws are punished at once. Carpcn-
ters and saw-mill men have no more to do
with them. Sawmakers, therefore, guard
the quality of their goods with jealous
care, and every saw-hand. circular band
cross-cut rip. keyhole. scroll. slSew-back
veneering, pit, buck. mulay right-hand
left-hand or any other variety-is indi-
vidually tested before ii leaves the factory
The making of saws, from the tiny
SGIOlA-SdN 10 Ailt ADA8 PIT saw AlhNl TIE
diminutive buzz saw of the dentist to the
seventy-inch circular used to splice up the
redwood of California. requires the best of
raw material and the most skiliful and eX-
pert Of steelworkers.
The best Swedish and American irons
only are put in the melting pots to make
the steel, and powerful steam hammers
work the ingots before they are rolled into
plates. sheets and fiat bars,
The largest saw-works in the world are
near Philadelphia. In the works the raw
material is bought in the shape Of soft.
tough Swedish and high-grade American
irons The crucible steel is made, ham
mered and rolled in the works. and every
thing is done on a large scale. Nearly
100000 saws of all kinds are turned out
from this immense plant yearly. and In the
thirty-eight buildings modern saw-making
at its best can be seen. The high perfec-
ton attained in the metalwOrkers' art,
however. is not in evidence until the saw
blade or disk. after being cut to shape and
having the teeth cut. reaches the temper
ing and hardening stage. The steelmaking,
the "cogging" of the ingots under the
steam hammering and the roliing-mill are
interesting, and so is the great shears
which cuts and shapes the saw blades and
circular plates for the buzz-saws. The
teeth-cutting machine is an attractive
piece of mechanism, but the hardening and
tempering are done by men, each one an
expert, a master of his art.
When the saw-blade reaches this de-
beyond its elastic limit il remains bent.
IN return to its original shape, and If bent
beyond its elastic limit it re remains bent.
To make a saw of Il the blade must be
tempered and each variety of saw must
have a different temper. The circular saw
which is to go through pine logs must
have a toughness, hardness and stiffness
different from the saw which is to cut up
~ Ff,4f F-w.
rolling mill. Still, the process, the simple
manipulation Of the blade and disk is
about the same. The desired results are
secured by variation in temperatures in
the hardening and annealing features,
the time in which the blades are kept in
the furnaces, the composition and tenn
pera lures of the tempering baths The
blades are first hardened by being heated
and then suddely cooled. The greatest
care must be exercised in dipping the
heated blade in the water, for If one side
cools quicker than the other the unequal
tension dstorts the blade and IL is warped.
The larger the saw the more difficult is
the process.
The workman poises the blade over the
bath. watching it keenly. The film Of
oxide on the steel changes color as it
cools, and when the proper tint glistens
on the blade 1t is plunged Kissing into the
water When it is cod the blade is hard,
but its toughness has disappeared, for it
is as brittle as glass. a hammer blow VIII
shatter the steel. to bits, for all its MOLE
cules are in state Of extreme tension,
ready to fly apart on the slightest provo
cation. To restore the toughness, the es-
sential elasticity, the temper must be
drawn" so the blade must be heated
again.
Here the mysterious art of tempering
is seen at its best. The workman gives
the steel just the right amount OF heat,
and then withdraws the blade from the
furnace. Again he watches the chame-
lion-like oxide or skim il changes and
blends from one color to another, some
times a pigeons-egg blue, an amber, a
straw, a yellow. or a deep-blue color
When the proper color appears the blade