Grade |
W-1 |
W-2 |
W-3 |
W-4 |
|
The impurity Content is not more than % |
Pb | -- | -- | -- | 0.001 |
Bi | -- | -- | -- | 0.001 | |
Sn | -- | -- | -- | 0.001 | |
Sb | -- | -- | -- | 0.001 | |
As | -- | -- | -- | 0.002 | |
Fe | 0.005 | 0.005 | 0.010 | 0.05 | |
Ni | 0.003 | 0.003 | 0.005 | 0.30 | |
Al | 0.002 | 0.002 | 0.005 | 0.005 | |
Si | 0.003 | 0.003 | 0.010 | 0.010 | |
Ca | 0.003 | 0.003 | 0.005 | 0.005 | |
Mg | 0.002 | 0.002 | 0.005 | 0.010 | |
Mo | 0.010 | 0.010 | 0.20 | 0.20 | |
P | 0.001 | 0.001 | 0.002 | 0.005 | |
C | 0.005 | 0.008 | 0.010 | 0.010 | |
O | 0.003 | 0.003 | 0.005 | 0.010 | |
N | 0.003 | 0.003 | -- | -- |