Brinell hardness is a typical hardness specification for cast iron products, especially for ductile iron and gray cast iron.
However, in the most international standards, cast iron hardness is not a necessary inspection specification. Only in Chinese standards, we could see the normal Brinell Hardness (HBS) range for common cast iron grades.
If the hardness is very important for your products, for example, you need the better abrasive resistance, then you should add one hardness requirement for your products, so the casting manufacturers could adjust the chemical composition to increase its hardness.
The following list is for the typical Brinell Hardness range for the main grades of ductile iron and grey cast iron.
Resonable Brinell Hardness Range of Ductile iron castings:
ISO 1083
Grade |
ASTM A536
Grade |
China GB1348
Grade |
Tensile strength
σb/MPa (min) |
Yield strength
σ0.2/MPa (min) |
Elongation
δ5 (％) |
Hardness
HBS |
400-18 |
60-40-18 |
QT400-18 QT400-18-LT |
400 |
250 |
18 |
130~180 |
400-15 |
60-42-10 |
QT400-15 |
400 |
250 |
15 |
130~180 |
450-10 |
60-45-12 |
QT450-10 |
450 |
310 |
10 |
160~210 |
500-7 |
70-50-05 |
QT500-7 |
500 |
320 |
7 |
170~230 |
600-3 |
80-55-06
80-60-03 |
QT600-3 |
600 |
370 |
3 |
190~270 |
700-2 |
100-70-03 |
QT700-2 |
700 |
420 |
2 |
225~305 |
800-2 |
120-90-02 |
QT800-2 |
800 |
480 |
2 |
245~335 |
900-2 |
- |
QT900-2 |
900 |
600 |
2 |
280~360 |
Resonable Brinell Hardness Range of Gray Iron castings:
ISO 185
Grade |
ASTM A48
Grade |
China GB9439
Grade |
Tensile strength
σb/MPa (min) |
Hardness
HBS |
100 |
- |
HT100 |
100 |
<170 |
150 |
No.20
No.25 |
HT150 |
150 |
125~205 |
200 |
No.30 |
HT200 |
200 |
150~230 |
250 |
No.35 |
HT250 |
250 |
180~250 |
300 |
No.40
No.45 |
HT300 |
300 |
200~275 |
350 |
No.50 |
HT350 |
350 |
220~290 |
|
