Children of this group are better than somewhat above average. They are unusually superior. Not more than 3 out of 100 go as high as 125 I Q, and only about 1 out of 100 as high as 130. In the schools of a city of average population only about... Read more of Very Superior Intelligence (i Q 120 To 140) at Intelligence Test.caInformational Site Network Informational
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Making Steel Balls
Steel balls are made from rods or coils according to size, st...

The Influence Of Size
The size of the piece influences the physical properties obta...

Molybdenum steels have been made commercially for twenty-five...

Affinity Of Nickel Steel For Carbon
The carbon- and nickel-steel gears are carburized separately...

Heat-treating Department
The heat-treating department occupies an L-shaped building. ...

Introduction Of Carbon
The matter to which these notes are primarily directed is the...

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

An Automatic Temperature Control Pyrometer
Automatic temperature control instruments are similar to the ...

High-carbon Machinery Steel
The carbon content of this steel is above 30 points and is ha...

Preventing Cracks In Hardening
The blacksmith in the small shop, where equipment is usually ...

Application Of Liberty Engine Materials To The Automotive Industry
The success of the Liberty engine program was an engineer...

Armor plate makers sometimes use the copper ball or Siemens' ...

Refining The Grain
This is remedied by reheating the piece to a temperature slig...

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

Judging The Heat Of Steel
While the use of a pyrometer is of course the only way to hav...

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

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

Steel Can Be Worked Cold
As noted above, steel can be worked cold, as in the case of ...

Open Hearth Process
The open hearth furnace consists of a big brick room with a l...

Care In Annealing
Not only will benefits in machining be found by careful anne...

Annealing Of High-speed Steel


For annealing high-speed steel, some makers recommend using ground
mica, charcoal, lime, fine dry ashes or lake sand as a packing
in the annealing boxes. Mixtures of one part charcoal, one part
lime and three parts of sand are also suggested, or two parts of
ashes may be substituted for the one part of lime.

To bring about the softest structure or machine ability of high-speed
steel, it should be packed in charcoal in boxes or pipes, carefully
sealed at all points, so that no gases will escape or air be admitted.
It should be heated slowly to not less than 1,450 deg.F. and the steel
must not be removed from its packing until it is cool. Slow heating
means that the high heat must have penetrated to the very core of
the steel.

When the steel is heated clear through it has been in the furnace
long enough. If the steel can remain in the furnace and cool down
with it, there will be no danger of air blasts or sudden or uneven
cooling. If not, remove the box and cover quickly with dry ashes,
sand or lime until it becomes cold.

Too high a heat or maintaining the heat for too long a period,
produces a harsh, coarse grain and greatly increases the liability
to crack in hardening. It also reduces the strength and toughness
of the steel.

Steel which is to be used for making tools with teeth, such as
taps, reamers and milling cutters, should not be annealed too much.
When the steel is too soft it is more apt to tear in cutting and
makes it more difficult to cut a smooth thread or other surface.
Moderate annealing is found best for tools of this kind.

Next: Tool Or Crucible Steel

Previous: Annealing

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 4583