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Tensile Test Specimen
Tensile test specimen
is also called tensile test bar, which
is used to test the tensile strength,
yield strength and elongation for the
cast
iron and
cast
steel materials. It is the most
important test method to iron and steel
castings.
Tensile strength and elongation are the
very important and main physical
properties for the iron and steel
castings.
Tensile strength (TS) is also
called as ultimate tensile strength (UTS),
often shortened as ultimate strength, is
the maximum stress that a material can
withstand while being stretched or
pulled before necking, which is when the
specimen's cross-section starts to
significantly contract. Tensile strength
is opposite of compressive strength and
the values can be quite different.
The tensile test specimen dimensions are
very important for the accurate test
result. There are many different
dimensions, such as 10mm, 12mm and 14mm
and 20mm, but main principle is the
effective length is 5 times of the
effective diameter. For example, 10mm
diameter with 50mm length, 12mm diameter
with 60mm length, 14mm diameter with
70mm length, and so on. Usually, most of
metal foundries in China use the 14mm
diameter as the standard test specimen.
This principle is suitable for both cast
iron and cast steel. Some clients,
especially big companies, may issue
their own standard to the tensile test
specimen dimensions. However, they
should obey this principle, otherwise,
the test result should not be taken as
correct.
As for the sampling point, it is better
to get the test specimen from the body
of castings, however, it is difficult
sometimes, so usually
Dandong Foundry will make the
test specimen during the production of
castings. These test specimen will
reflect the tensile strength of the
castings made in the same furnace.
As for the tensile test machines, please
there are many types. For the old type,
we have to calculate the results by the
manual, but for the new type of test
machine, the computer will calculate the
results for you, but all types of test
machines are basing on the same theory.
For the photos of tensile test specimen
and test machines, please check Dandong
Foundry Blog.
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