4 Hardness
Conversion Chart
ROCKWELL
BRINELL
C
B
D ia.
in m m .,
Vicker
or
150 kg.
load
100 kg.
load
Tensile
3000
kg. load
Hardness
Firth
120
Diamond
1/16
in. dia.
Scleroscope
Strength
10 mm.
ball
No.
Hardness
No.
Cone
ball
No.
1000
psi.
2.0 5
8 9
8
4 4
0
2.1 0
8 5
7
4 2
0
2.1 5
8 1
7
4 0
1
2.2 0
7 8
0
1 1
5 0
7 0
1
0 6
3
3 4
2.2
5 7
4 5
1
0 5
0 6
8
1 0
0
3 6
8
2.3 0
7 1
2
9 6
0 6
6
9 5
3
5 2
2.3
5 6
8 2
8
8 5
6 4
9
1
3 3
7
2.4 0
6 5
3
8 2
0 6
2
6 7
3
2 4
2.4
5 6
2 7
7
6 5
6 0
8
4
3 1
1
2.5 0
8 0
1
7 1
7 5
8
8 1
2
9 8
2.5
5 5
7 8
6
7 5
5 7
7
8
2 8
7
2.6 0
5 5
5
6 3
3 5
5
1 2
0
7 5
2
7 6
2.6
5 5
3 4
5
9 8
5 3
1
1 9
7
2
2 6
6
2.7 0
5 1
4
5 6
7 5
2
1 1
9
7 0
2
5 6
2.7
5 4
9 5
5
4 0
5 0
1
1 7
6
7
2 4
7
2.6 0
4 7
7
5 1
5 4
9
1 1
7
6 5
2
3 8
2.8
5 4
6 1
4
9 4
4 7
1
1 6
6
3
2 2
9
2.9 0
4 4
4
4 7
2 4
6
1 1
5
6 1
2
2 0
2.9
5 4
2 9
4
5 4
4 5
1
1 5
5
9
2 1
2
3.0 0
4 1
5
4 3
7 4
4
1 1
4
5 7
2
0 4
3.0
5 4
0 1
4
2 0
4 2
1
1 3
5
5
1 9
6
3.1 0
3 8
8
4 0
4 4
1
1 1
2
5 4
1
8 9
3.1
5 3
7 5
3
8 9
4 0
1
1 2
5
2
1 8
2
3.2 0
3 6
3
3 7
5 3
8
1 1
0
5 1
1
7 6
3.2
5 3
5 2
3
6 3
3 7
1
1 0
4
9
1 7
0
3.3 0
3 4
1
3 5
0 3
6
1 0
9
4 8
1
6 5
3.3
5 3
3 1
3
3 9
3 5
1
0 9
4
6
1 6
0
3.4 0
3 2
1
3 2
7 3
4
1 0
8
4 5
1
5 5
3.4
5 3
1 1
3
1 6
3 3
1
0 8
4
4
1 5
0
3.5 0
3 0
2
3 0
5 3
2
1 0
7
4 3
1
4 6
3.5
5 2
9 3
2
9 6
3 1
1
0 6
4
2
1 4
2
3.6 0
2 8
5
2 8
7 3
0
1 0
5
4 0
1
3 8
3.6
5 2
7 7
2
7 9
2 9
1
0 4
3
9
1 3
4
3.7 0
2 6
9
2 7
0 2
6
1 0
4
3 8
1
3 1
3.7
5 2
6 2
2
6 3
2 6
1
0 3
7
1
2 8
3.8
0 2
5 5
2
5 6
2 5
1
0 2
3
7
1 2
5
3.8 5
2 4
8
2 4
8 2
4
1 0
2
3 6
1
2 2
3.9
0 2
4 1
2
4 1
2 3
1
0 0
3
5
1 1
9
3.9 5
2 3
5
2 3
5 2
2
9 9
3
4
1 1
6
