| Material | n |
| Polyvinyl chloride pipe | 0.01 |
| steel | 0.011 |
| ductile iron | 0.013 |
| cast iron | 0.013 |
| cement lined pipe | 0.015 |
| concrete pipe | 0.013 |
| vitrified clay pipe | 0.013 |
| fiberglass reinforced plastic | 0.01 |
| corrugated metal pipe | 0.024 |
| HDPE, smooth interior | 0.01 |
| HDPE,corrugated interior(4-6 in) | 0.015 |
| HDPE,corrugated interior(8 in) | 0.016 |
| HDPE,corrugated interior(10 in) | 0.017 |
| HDPE,corrugated interior(12-15 in) | 0.018 |
| HDPE,corrugated interior(18-24 in) | 0.02 |