The Cheyenne daily leader. [volume] (Cheyenne, Wyo.) 1870-1884, 1882-04-01

Al ing VI PGSCi' y
Steel is n of the most valuable met.
ais used in the mechanic arts, and re-
quires great care in forging, hardening,
;cmpering, annealing and general man
agement. Tons of the very best steel
are condemned as bad, when nothing
but the forging has reduced it to that
condition, and all from a lack of knowl.
edge in the management.
In forging cast steel, the fire should
be regulated by the size of the work. q
prefer a hollow fire to be fed with coke
70 ascertain the heat of the steel, draw
it out of the fire often, for it requires to
be carefully watched to get the proper
heat. If not hot enough, thrust it quick.
ly in again. The proper degree of hea;
is to be judged by the eye, and care
should be taken not to heat higher than
is absolutely necessary to effect the de.
sired purpose, and to use as few heat.
as possible. Too frequent heating and
overheating steel abstracts the carbon,
gradually reducing it to the state OF
forged iron. 1t is the opinion of q great
many that, so long as the steel does not
fly to pieces when struck with the ham.
mer, it is not toe hot; but it is an enron.
eous idea, as is easily proved when il
comes to be hardened, and particularly
when it come to be used.
An excellent composition for welding
cast steel is prepared by boiling together
sixteen parts of boraX and one of sal-am.
monica over a slow fire for an hour.
When cold, grind it into a powder. The
steel must then be made aS hot rs it will
conveniently bear, and the composition
used the same rs sand.
Steel punches, or other small instru-
mcnt-. particularly engraved dies, when,
by acci !cntal exposure to too great heat
they Lave become spoiled, or, us the
blacksmith SAYS, burned, may he re.
stored by tho following mixture: Two
ounces of bichromate of POTASH. one
ounce If pure nitre, one ounce gum
alocs. n ounce gun arabic and two
ounces of resin. The whole having been
well powdered and mixed. the piece OF
steel is heated to n low, red heat, and
the powder sprinkled over it. 1t is then
heated again to a low, red heat and
cooled. This makes the piece very hard
again. The amount of nitro may be
doubled, and that of the resin ten times
greater to produce a higher temper.
In tempering a tool for boring cylin-
ders, turning rolls, or any large pieces
of cast iron, let it be as hard as water
will make it, taking care not TO heat il
moro than TO Il cherry red. In the sec.
ond heating, after the tool is hardened,
the first %pcrceptible tint is Il light straw
color, which makes its appearance when
the heat reaches 430 degrees Fahrenheit.
This gives the metal a maximum Of hard
ness. with n certain amount of elasticity,
fitting il for lancets, razors and surgi-
cal Instruments. At 40 degrees a full
yellow is produced, which is the temper
emploi ed for penknives, scalpels and
fine cutlery. The temperature of 400
degrees gives n brownish-orange, suit
able for shears and chisels used for cut
ting iron. At 510degrees the brownish.
yellow becomes flecked with purple, the
tint for p~ocket-knives. Five hundred
and twenty degrees gives a blush purple.
fit for table cutlery; while the different
shades of blue from $50 degrees to $40
degrees indicate a temper proper for
watch springs, sword blades, saws, and
instruments requiring great elasticity.
Beyond this temperature the metal be.
comes too soft TO be used for cutting
instruments.
The temper greatly depends on the
quantity of carbon that is in the steel.
This the practical nan soon finds out,
and he tempers or draws down the tool
accordingly.
In Switzerland. razors, pocket-knives,
etc., made from English cast steel are
tempered by immersing the blades at q
dark cherry red into a bath composed Of
four parts of tinely-powdered yellow
resin, Two parts of fish oil, to which is
added, in a very hot state, one part Of
melted tallow, and allowing them to
cool perfectly; after which they are
heated without wiping them, and hard.
ened in water in the ordinary way. The
blades hardened bythis process are found
t o be more uniformly tempered than by
any other. making it possible to produce
an exceedingly fine cutting edge.-Bs
T. j. Bodirttch, in american MachiniSL