T he halved joint is frequently known as half-lapping, and sometimes as checking and half-checking. In the majority of cases it is made by halving the two pieces, i.e., by cutting half the depth of the wood away. There are, however, exceptions ... Read more of The Halved Joint at Wood Workings.caInformational Site Network Informational
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Steel Making

Hints For Tool Steel Users
Do not hesitate to ask for information from the maker as to t...

Compensating Leads
By the use of compensating leads, formed of the same materia...

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

Sulphur
SULPHUR is another element (symbol S) which is always found i...

The Packing Department
In Fig. 56 is shown the packing pots where the work is packe...

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

Mushet And Bessemer
That Mushet was "used" by Ebbw Vale against Bessemer is, perh...

Machineability
Reheating for machine ability was done at 100 deg. less than ...

Suggestions For Handling High-speed Steels
The following suggestions for handling high-speed steels are ...

High Speed Steel
For centuries the secret art of making tool steel was handed ...

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

Placing The Thermo-couples
The following illustrations from the Taylor Instrument Compan...

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

The Electric Process
The fourth method of manufacturing steel is by the electric f...

Instructions For Working High-speed Steel
Owing to the wide variations in the composition of high-speed...

Gears
The material used for all gears on the Liberty engine was sel...

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

Effect Of Different Carburizing Material
[Illustrations: FIGS. 33 to 37.] Each of these different p...

Effect Of A Small Amount Of Copper In Medium-carbon Steel
This shows the result of tests by C. R. Hayward and A. B. Joh...

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



Standard Analysis






Category: HIGH-SPEED STEEL

The selection of a standard analysis by the manufacturer is the
result of a series of compromises between various properties imparted
to the steel by the addition of different elements and there is a
wide range of chemical analyses of various brands. The steel, to
be within the range of generally accepted analysis, should contain
over 16 per cent and under 20 per cent tungsten; if of lower tungsten
content it should carry proportionately more chromium and vanadium.

The combined action of tungsten and chromium in steel gives to it the
remarkable property of maintaining its cutting edge at relatively high
temperature. This property is commonly spoken of as red-hardness.
The percentages of tungsten and chromium present should bear a
definite relationship to each other. Chromium imparts to steel
a hardening property similar to that given by carbon, although
to a less degree. The hardness imparted to steel by chromium is
accompanied by brittleness. The chromium content should be between
3.5 and 5 per cent.

Vanadium was first introduced in high-speed steel as a scavenger,
thereby producing a more homogeneous product, of greater density
and physical strength. It soon became evident that vanadium used
in larger quantities than necessary as a scavenger imparted to
the steel a much greater cutting efficiency. Recently, no less an
authority than Prof. J. O. Arnold, of the University of Sheffield,
England, stated that high-speed steels containing vanadium have
a mean efficiency of 108.9, as against a mean efficiency of 61.9
obtained from those without vanadium content. A wide range of
vanadium content in steel, from 0.5 to 1.5 per cent, is permissible.

An ideal analysis for high-speed steel containing 18 per cent tungsten
is a chromium content of approximately 3.85 per cent; vanadium, 0.85
to 1.10 per cent, and carbon, between 0.62 and 0.77 per cent.





Next: Detrimental Elements

Previous: High Speed Steel



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