Mitutoyo HM-200A Series - Vickers Hardness; What Is Vickers Hardness

4. Hardness test procedure
No. 99MBG127A
4-13
4.2.1 Vickers hardness
4.2.1.1 What is Vickers hardness
Vickers hardness can be derived by the value (F/S) that is the test force "F" divided by the surface
area of the indentation "S" that is calculated by the diagonal line length "d" (average of 2 diagonal
lines), where the indentation is made by a diamond indenter shaped right pyramid with a aquare
base with an angle between opposote faces at the vertex θ of 136 degrees.
Fig. 4-1 Reference figure of Vickers hardness Fig. 4-2 Indentation of Vickers hardness test
<Vicker's hardness calculation method>
Where
HV: Vickers hardness
k: Constant, k=1/g
ｎ
=1/9.806650≒0.102
F: Test force [N]
S: Indentation surface area
d: Average length of 2 diagonal lines of indentation [mm], d=(d
1
+d
2
)/2
θ: Angle between opposote faces at the vertex of diamond indenter (136°)
g
ｎ
: Standard gravitational acceleration
Where the surface of the specimen must be parallel to the top surface of the stage.
d
1
d
2
22
1891.0
2
sin2
102.0102.0
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ＨＶ＝ｋ
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