| 等 级 |
Cu(% ) |
Pb(%) |
Zn(%) |
| 1 |
≧24 |
--- |
--- |
| 2 |
≧22 |
--- |
--- |
| 3 |
≧20 |
--- |
--- |
| 4 |
≧18 |
--- |
--- |
| 5 |
≧16 |
≦9 |
≦12 |
| 6 |
≧14 |
≦9 |
≦12 |
| 7 |
≧12 |
≦9 |
≦12 |
| 8 |
≧10 |
≦9 |
≦12 |
| 9 |
≧8 |
≦9 |
≦12 |
