Engineering Materials
Comparison of Hardness Scales: The following table compares the various hardness
scales. Assumptions are that the metal tested is homogeneous
to a depth several times that of the indentation. To the extent that the metal being
tested is not homogeneous, errors are introduced because different loads and different
shapes of penetrators meet the resistance of metal of varying hardness, depending on the
depth of indentation. Another source of error is introduced in comparing the hardness of different materials as measured on different hardness scales. This error arises from the fact that in any hardness test, metal that is severely cold-worked actually supports the penetrator,
and different metals, different alloys, and different analyses of the same type of alloy
have different cold-working properties.
Comparative Hardness Scales for Steel Table
Rockwell
C-Scal
eHardness
Number
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Diamond
Pyramid
Hardness
Number
Vickers
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Brinell Hardness Number
10-mm Ball, 3000-kgf Load
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Rockwell Superficial Hardness Number
Superficial Diamond Indenter
|
Shore
Scleroscope
Hardness Number
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|
A-Scale
60-kgf
Load
Diamond Indenter
|
D-Scale
100-kgf
Load
Diamond Indenter
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