49 C.F.R. § 178.347-2
Material and thickness of material
(a) The type and thickness of material for DOT 407 specification cargo tanks must conform to § 178.345-2, but in no case may the thickness be less than that determined by the minimum thickness requirements in § 178.320(a). Tables I and II identify the specified minimum thickness values to be employed in that the determination:
| Volume capacity in gallons per inch | 10 or less | Over 10 to 14 | Over 14 to 18 | Over 18 to 22 | Over 22 to 26 | Over 26 to 30 | Over 30 |
|---|---|---|---|---|---|---|---|
| Thickness (MS) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (HSLA) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (SS) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (AL) | 0.160 | 0.160 | 0.173 | 0.187 | 0.194 | 0.216 | 0.237 |
| Volume capacity in gallons per inch | 10 or less | Over 10 to 14 | Over 14 to 18 | Over 18 to 22 | Over 22 to 26 | Over 26 to 30 | Over 30 |
|---|---|---|---|---|---|---|---|
| Thickness (MS) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (HSLA) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (SS) | 0.100 | 0.100 | 0.115 | 0.129 | 0.129 | 0.143 | 0.156 |
| Thickness (AL) | 0.151 | 0.151 | 0.160 | 0.173 | 0.194 | 0.216 | 0.237 |
(b) [Reserved]