| Class L: | Coils up to 32 % of the payload P of the container |
| Class M: | Coils from 32 % to 49 % of the payload P of the container |
| Class H: | Coils from 49 % to 65 % of the payload P of the container |
| Class XH: | Coils above 65 % of the payload P of the container |
Coils of class L (light) may be loaded three or more in number with largely utilising the container payload. The layout of stowage must primarily regard to the transverse strength of the container.
Coils of class M (medium) may only be loaded two per container. Also in this case, the transverse strength of the container places substantial demands on the layout of the stowage.
Coils of the classes H (heavy) and XH (extra heavy) may only be loaded one per container. The layout of stowage must take the transverse strength as well as the longitudinal strength of the container into account. For coils of the class XH the safeguarding of longitudinal strength requires a bedding of steel beams, because timber cannot spread the load with reasonable expense.
The correlation between weight (mass) and size of a coil cannot clearly be defined, because the three dimensions breadth b, outer diameter d and eye diameter di are mutually variable to a certain extent. If the dimensions are known, the mass m may be calculated under the assumption of an effective density of ρ = 7.6 t/m³.
m = 7.6 · b · (d² - di²) ·
/4 [t] with the dimensions in metres