Heat
Treatment 
For a
tool steel to perform effectively a component when machined
will usually require heat treatment. This will enable the tool
to develop the characteristic properties required for a high
hardness with good wear, abrasion and impact values, which vary
with each specification. Refer to our tool steel page where
we offer specification data sheet on our more popular specifications.
For heat treatment a tool steel component requires preheating
(to avoid cracking and unnecessary distortion of the component),
then it is raised to its final hardening temperature. An important
point is the great necessity of having the tool steel uniformly
heated through or as generally termed "well soaked".
To achieve a high hardness the steel then requires rapid cooling.
The name given to this process is "quenching". Dependant
on specification the steel may be quenched in oil or cooled
in air or inert gas. The steel is now extremely brittle and
under great stress. If used in this condition the steel would
probably shatter and it is possible the steel may even crack
if left for any time in this condition. Therefore, as soon as
the steel is quenched it requires tempering immediately. The
tempering temperature is dependant on what hardness is required
for the component. The steel is heated to the required temperature
and held at this temperature for a minimum of one hour per inch
of thickness (minimum 2 hours) and then allowed to cool. Certain
tool steels require a double tempering. Certain steels can be
given surface treatment, such as nitriding, when required.
For your
guidance refer to our Colour Charts for
Forging, Hardening and Tempering.
Testing
Facilities
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West
Yorkshire steel offer a full consultation service covering
technical or heat treatment queries which may arise. Individual
leaflets covering heat treatment and applications of steel
specifications can be provided. Certification available
on all materials. Our facilities include hardness, chemical,
spark and dye penetrant testing. For your reference please
refer to our Hardness
Conversion Chart.
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