Steel is the opposite of furniture: containers reach their weight limit long before they are full. Overloading is not just a safety issue — in the US it can mean fines, refused pickups and expensive transloading.
Know the real limit: US roads, not the container
A container may be rated for over 25 tonnes of cargo, but US federal road limits (80,000 lbs gross vehicle weight, about 36 tonnes including truck and chassis) are lower in practice. As a rule of thumb, plan around 19–20 tonnes of cargo for standard trucking and ask your forwarder about tri-axle chassis or permits for heavier loads.
20' or 40'?
| 20' | 40' | |
|---|---|---|
| Typical use | Dense steel: uprights, beams, plates | Long components, mixed lighter shelving |
| Cost per tonne | Usually lower for heavy cargo | Better when volume, not weight, is the limit |
| Long items | Up to ~5.9 m | Up to ~12 m |
Weight distribution and securing
- Spread weight evenly across the floor; avoid concentrated loads in the middle.
- Use timber bracing, lashing straps to container lashing points and dunnage.
- Declare an accurate VGM (verified gross mass) — mandatory under SOLAS.
Rust: the quiet claim
Condensation during a month at sea can rust bare or lightly coated steel. Use VCI (vapour corrosion inhibitor) film or paper, desiccants, and avoid loading wet steel. Powder-coated racks need corner protection to avoid chips that later rust.
Related: DDP for steel racks · export packing basics.