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Steel Making

A Satisfactory Luting Mixture
A mixture of fireclay and sand will be found very satisfactor...

Blending The Compound
Essentially, this consists of the sturdy, power-driven separa...

Pyrometry And Pyrometers
A knowledge of the fundamental principles of pyrometry, or th...

Impact Tests
Impact tests are of considerable importance as an indication ...

Heat-treating Equipment And Methods For Mass Production
The heat-treating department of the Brown-Lipe-Chapin Company...

Lathe And Planer Tools
TO FORGE.--Gently warm the steel to remove any chill is parti...

Nickel may be considered as the toughest among the non-rare a...

Placing Of Pyrometers
When installing a pyrometer, care should be taken that it re...

Hardening High-speed Steels
We will now take up the matter of hardening high-speed steels...

Annealing To Relieve Internal Stresses
Work quenched from a high temperature and not afterward tempe...

Detrimental Elements
Sulphur and phosphorus are two elements known to be detrimen...

Heat Treatment Of Punches And Dies Shears Taps Etc
HEATING.--The degree to which tools of the above classes shou...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundr...

PHOSPHORUS is an element (symbol P) which enters the metal fr...

Liberty Motor Connecting Rods
The requirements for materials for the Liberty motor connecti...

Testing And Inspection Of Heat Treatment
The hard parts of the gear must be so hard that a new mill f...

There is no mystery or secret about the proper annealing of d...

Protectors For Thermo-couples
Thermo-couples must be protected from the danger of mechanica...

Take Time For Hardening
Uneven heating and poor quenching has caused loss of many ve...

Testing And Inspection Of Heat Treatment


The hard parts of the
gear must be so hard that a new mill file does not bite in the
least. Having passed this file test at several points, the gears go
to the center-punch test. The inspector is equipped with a wooden
trough secured to the top of the bench to support the gear, a number
of center punches (made of 3/4-in. hex-steel having points sharpened
to an angle of 120 deg.) and a hammer weighing about 4 oz. With
these simple tools, supplemented by his skill, the inspector can
feel the depth and quality of the case and the condition of the
core. The gears are each tested in this way at several points on
the teeth and elsewhere, the scrap gear being also subjected to
the test. Finally, the scrap gear is securely clamped in the
straightening press shown in Fig. 57. With a 3-1/2-lb. hammer and
a suitable hollow-ended drift manipulated by one of Sandow's
understudies, teeth are broken out of the scrap gear at various
points. These give a record confirming the center-punch tests,
which, if the angle of the center punch is kept at 120 deg. and
the weight of the hammer and blow are uniform, is very accurate.

After passing the center-punch test the ends of the teeth are peened
lightly with a hammer. If they are too hard, small particles fly
off. Such gears are drawn in oil at a temperature of from 300 to
350 deg.F., depending on their hardness. Some builders prefer to have
the extreme outer ends of the teeth drawn somewhat lower than the
rest. This drawing is done on gas-heated red-hot plates, as shown
at A in Fig. 58.

Nickel steel, in addition to all the tests given to carbon steel,
is subjected to a Brinell test. For each steel, the temperature
and the period of treatment are specific. For some unknown reason,
apparently like material with like treatment will, in isolated
cases, not produce like results. It then remains for the treatment
to be repeated or modified, but the results obtained during inspection
form a valuable aid to the metallurgist in determining further

Next: Temperature Recording And Regulation

Previous: Affinity Of Nickel Steel For Carbon

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