| Element(ppm max) | Grade FNW-1 | Grade FNW-2 |
| Nb |
10 |
30 |
| O | 200 | 200 |
| N | 30 | 60 |
| C | 20 | 30 |
| H | 15 | 15 |
| Si | 30 | 300 |
| Fe | 20 | 30 |
| W | 20 | 20 |
| Mo | 20 | 20 |
| Ti | 5 | 5 |
| Cr | 20 | 25 |
| Ni | 20 | 25 |
| Ca | 10 | 10 |
| Sn | 5 | 5 |
| Al | 5 | 5 |
| Na | 10 | 20 |
| Diameter | ≥0.15 | ≥0.15 |
| Element(ppm max) | Grade FNW-1 | Grade FNW-2 |
| Nb |
10 |
30 |
| O | 200 | 200 |
| N | 30 | 60 |
| C | 20 | 30 |
| H | 15 | 15 |
| Si | 30 | 300 |
| Fe | 20 | 30 |
| W | 20 | 20 |
| Mo | 20 | 20 |
| Ti | 5 | 5 |
| Cr | 20 | 25 |
| Ni | 20 | 25 |
| Ca | 10 | 10 |
| Sn | 5 | 5 |
| Al | 5 | 5 |
| Na | 10 | 20 |
| Diameter | ≥0.15 | ≥0.15 |