■ Relationship Between Vickers Hardness and the Minimum Allowable Thickness of a Specimen
Hardness symbol
Test force
F:N
4.903x10 -3
HV0.0005
Diagonal length of indentation
Minimum thickness of specimen
9.807x10 -3 19.61x10 -3 29.42x10 -3 49.03x10 -3 98.07x10 -3
0.001 0.002 0.003 0.005
0.001 0.002 0.003 0.005 t:mm
d:mm
0.001 0.002 0.003 0.005
0.01 0.02 0.03 0.05
Vickers hardness HV
d
0.1961 0.2942 0.4903 0.9807
2000 1000
0.01 0.02 0.03 0.05
0.01 0.02 0.03 0.05 0.1
0.1 0.2 0.3 0.5
500 300 200 100
1.961 2.942 4.903 9.807 19.61 29.42 49.03 98.07 196.1 294.2 490.3
F d 2
HV=0.1891 t>1.5d h ≒ d/7 t: Thickness of specimen (mm) d: Diagonal length (mm) h: Depth of indentation (mm)
0.1 0.2 0.3 0.5
1 2 3 5
0.2 0.3 0.5
50 30 20
[Example] Specimen thickness t: 0.15mm Specimen hardness: 185HV1 Test force F: 9.807N (1kgf) Diagonal length d: 0.1mm
1 2 3
1 2
10 20 30 50
■ Relationship Between Rockwell/Rockwell Superficial Hardness and the Minimum Thickness of a Specimen
1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 10 20 30 40 50 60 70 80 90 100
3.3 3.15 3 2.85 2.7 2.55 2.4 2.25 2.1 1.95 1.8 1.65 1.5 1.35 1.2 1.05 0.9 0.75
1.4 1.2 1.0 0.8 0.6 0.4 0.2 0
10 20 30 40 50 60 70 80 90 100
20 30 40 50 60 70 80 90 100
Rockwell hardness
Rockwell Superficial hardness
Rockwell hardness
K
■ Rockwell Hardness Scales
■ Rockwell Superficial Hardness Scales Scale Indenter Test force Application 15-N Diamond 147.1N 30-N 294.2N
Scale
Indenter
Test force
Application
A D C
588.4N Carbide, sheet steel Case-hardened steel 980.7N
Thin surface-hardened layer on steel such as carburized or nitrided
Diamond
45-N 15-T 30-T 45-T
441.3N 147.1N 294.2N 441.3N 147.1N 294.2N 441.3N 147.1N 294.2N 441.3N 147.1N 294.2N 441.3N
Steel (100HRB or more to 70HRC or less)
1471N
F
588.4N Bearing metal, annealed copper Brass
Sphere of 1.5875mm diameter
Sphere of 1.5875mm diameter Sphere of 3.175mm diameter Sphere of 6.35mm diameter Sphere of 12.7mm diameter
Sheet of mild steel, brass, bronze, etc.
B
980.7N 1471N
Hard aluminum alloy, beryllium copper, phosphor bronze
G H
15-W Sphere of 3.175mm diameter 30-W 45-W
588.4N Bearing metal, grinding wheel Bearing metal Bearing metal 980.7N 1471N
Plastic, zinc, bearing alloy
E
K
15-X 30-X 45-X 15-Y 30-Y 45-Y
Sphere of 6.35mm diameter Sphere of 12.7mm diameter
L
588.4N 980.7N 1471N 588.4N 980.7N 1471N
Plastic, zinc, bearing alloy
Plastic, lead
M
P R S V
Plastic, zinc, bearing alloy
Plastic, lead
K-18
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