Informational Site NetworkInformational Site Network
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Complete Calibration Of Pyrometers
For the complete calibration of a thermo-couple of unknown e...

Chromium when alloyed with steel, has the characteristic func...

Classifications Of Steel
Among makers and sellers, carbon tool-steels are classed by g...

Steel For Chisels And Punches
The highest grades of carbon or tempering steels are to be re...

Correction By Zero Adjustment
Many pyrometers are supplied with a zero adjuster, by means ...

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

Brown Automatic Signaling Pyrometer
In large heat-treating plants it has been customary to mainta...

ANNEALING can be done by heating to temperatures ranging from...

The Penetration Of Carbon
Carburized mild steel is used to a great extent in the manufa...

The Quenching Tank
The quenching tank is an important feature of apparatus in c...

Cyanide Bath For Tool Steels
All high-carbon tool steels are heated in a cyanide bath. Wi...

Connecting Rods
The material used for all connecting rods on the Liberty engi...

Although it is possible to work steels cold, to an extent de...

Annealing Work
With the exception of several of the higher types of alloy s...

Tool Or Crucible Steel
Crucible steel can be annealed either in muffled furnace or b...

Quality And Structure
The quality of high-speed steel is dependent to a very great ...

Critical Points
One of the most important means of investigating the properti...

Silicon prevents, to a large extent, defects such as gas bubb...

MANGANESE is a metal much like iron. Its chemical symbol is M...

Application To The Automotive Industry
The information given on the various parts of the Liberty eng...

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

Add to Add to Reddit Add to Digg Add to Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network

Viewed 3289