Recommended Strength by Location | Internal - Unflagged Windspeed Rating | External - Unflagged Windspeed Rating | Internal - Flagged Windspeed Rating | External - Flagged Windspeed Rating | Base Dia. (in.) | Top Dia. (in.) | Wall Thickness (in.) |
US Interior and West Coast (Standard Duty) | 118 | 118 | 85 | 85 | 8 | 3.5 | 0.188 |
Eastern & Southern Inland Coastal (Heavy Duty) | 185 | 185 | 115 | 115 | 10 | 4 | 0.188 |
Coastal Hurricane Areas (Ultra Heavy Duty) | 230 | 230 | 150 | 150 | 10 | 4 | 0.312 |