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 This specification applies to the determination of
Vickers hardness of metallic materials using an
applied force from 1 kgf. to 120 kgf. Part B is applicable to the verification
of the Vickers hardness testing machines. And, part C is in reference to the
calibration of standardized test blocks. Complete specifications may be obtained
from
ASTM International.
This standard includes two classes
of standardized tests: the Routine test (with
routine accuracy), and the Verification, Laboratory, or Referee Test (with a
much higher degree of accuracy required). WMT&R specializes in the Referee
Test.
The Vickers Hardness Test consists of a small pyramid shaped diamond indenter with an
apical angle of 136°, which is pressed into the test sample at a predetermined
load. The resulting indentation is then measured in both axis from tip to tip.
The average of the two axis measurements is then converted into a Vickers
Hardness number by the use of a formula, or more often a chart based on the
formula. When choosing the test load, the highest load that can be performed on
the specimen will give the most accurate results. A higher load produces a
larger indentation with better measurement resolution and therefore, more
reliable results. |
