ISO container

In brief

‍An ISO container is an internationally standardized large-capacity steel shipping container whose dimensions, corner fittings, strength, and locking mechanisms are defined by the International Organization for Standardization (ISO)—specifically ISO 668 and ISO 1496. Thanks to this global standardization, the ISO container forms the foundation of modern logistics: it can be transferred seamlessly between container ships, freight trains, and truck chassis without the need to repack the cargo (intermodal transport).  

What is an ISO container used for?

ISO containers form the backbone of the global economy and modern construction infrastructure:

  • Intermodal freight transport: Seamless global transport of general cargo, raw materials, electronics, and vehicles by ship, rail, and truck.  
  • Stationary storage: Dry, windproof, and watertight (WWT) storage for tools, inventory, and supplies in trade, industry, and retail.  
  • Basis for custom builds & modular architecture: A universal shell for conversion into office containers, test benches, workshop containers, technical rooms, emergency shelters, or tiny houses.  
  • Defense & disaster relief: Deployable workspaces and functional units (GCS, field hospitals, command centers) for the armed forces, civil protection agencies, and relief organizations.  

Defining the terms: ISO container vs. shipping container vs. storage container / site container

  • ISO container: The legal and technical umbrella term. It defines all containers that strictly adhere to global ISO standards, feature standardized corner castings, and are stackable for maritime transport..  
  • Shipping container: A colloquial synonym for the classic ISO standard container (dry van) made of Corten steel, used for maritime logistics..  
  • Storage / material container (site container): Lighter sheet metal structures (e.g., made of galvanized steel or insulation panels). They often lack ISO certification, are not approved for stacking on ships, and do not carry a valid CSC plate..  

Frequently Asked Questions (FAQ)

What do the metrics TEU and FEU mean for ISO containers?

TEU (Twenty-foot Equivalent Unit) describes the unit of measurement equivalent to a 20-foot container. FEU (Forty-foot Equivalent Unit) corresponds to a 40-foot container. In logistics, two 20-foot ISO containers occupy exactly the same footprint as one 40-foot FEU container..  

Why is a 20-foot ISO container not exactly 20 feet long?

To ensure that two 20-foot containers can be placed one after the other on a ship or railcar while taking up the exact same length as a 40-foot container (12,192 mm), including the gap for the twistlock mechanism, a 20-foot container actually measures 19 feet 10.5 inches (6,058 mm).  

What is the function of ISO corner castings?

The eight standardized cast steel corners are the heart of the ISO system. They allow for handling by crane spreaders and reach stackers, as well as secure locking to truck chassis, railcars, or other containers using twistlocks.

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