In-depth Guide to Shipping Container Materials – What Are They Made Of?

Curious what shipping containers are made of? Look around, and you’ll see shipping containers everywhere. While the original idea behind their invention was to help ferry goods across the waters safely, people nowadays are using them as offices, homes, cafes, swimming pools, and more. It shouldn’t surprise us too much as we’re living in a fast-evolving world.

I’m sure you’re aware shipping containers are available in all sorts of sizes and shapes. But do you know how they’re made? And what type of steel do manufacturers in the shipping industry use to make them? In this article, we explain how shipping containers are made, including the shipping container materials used to assemble them.


What Are Shipping Containers Made Of?

shipping container materials - made of steel

A shipping container consists of corrugated wall panels, cargo doors, cross members, and frames. All these components are made using Corten steel.

Corten steel, also known as weathering steel, is the chief material that constitutes shipping containers.

But why corten steel?

While other types of steel require painting to prevent rusting, Corten steel is different. It stands out as the only group of steel alloys that’s rust-resistant. For this reason, container manufacturers prefer Corten steel because it requires no painting. In addition, it’s weldable.

Besides the main body, other components constitute a shipping container, and not all of these components are built from Corten steel. However, one thing is for sure. All materials used are carefully selected to ensure the containers are solid, robust, secure, and weatherproof.

Components of a Shipping Container

Container manufacturers will include the following unique features in most shipping containers:

1. Corner Castings

Corner castings are the corner posts found at every intersection where two corrugated wall panels meet.

The posts are reinforced to ensure they provide solid support to the container. In order to connect the shipping containers to anchor points or other containers, corner castings typically have openings. What these openings do is allow for twist-lock connectivity.

Additionally, corner castings are designed so that they’re strong enough to allow successful crane rigging, which should be possible whether the container is empty or loaded to the maximum.

2. Twist Locks

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Twist locks are components that connect shipping containers to other containers or anchor points safely. You fit its end piece into the corner casting, enabling you to lift the container and lock it either to a transporting vehicle or any other desired position.

Often, we use a lever to pivot the containers.

3. Cross Members

To support the floor of the shipping containers, manufacturers employ joists or beams known as cross members.

In addition to offering support, the cross members ensure a gap is left between the flooring and the ground. That way, the container floor doesn’t sit on the ground directly. This is vital in ensuring that no moisture from the ground beneath finds its way into the container.

Ever wondered why many container structures don’t have a foundation? Whether the container is a ground-level home or office, in most cases, they won’t have it, thanks to the cross members of the shipping container floor. The cross members raise the structure some distance above the ground, mitigating any risk of damage that may result from natural factors.

4. Forklift Pockets

Forklift pockets are the openings found near the bottom edge of shipping containers. Standard containers (usually 20 ft long) and most containers 40 ft long feature two forklift pockets. The purpose of these reinforced openings is to fit forklift tines.

To move or lift the containers, you’ll need to place the tines inside the pockets using the forklifts.

However, it is worth noting that there are structures with modifications that make lifting with forklifts dangerous and unsuitable. Furthermore, some shipping containers, such as the modified 40-foot ones, weigh more due to modifications. Forklifts may not be able to support such weight.

5. Cargo Doors

cargo doors

Shipping containers feature two steel doors at one end of the container. In some containers, though, you’ll find the cargo doors on both ends or even on the side walls.

Originally, the doors were designed for reasons based on security and weather resistance. They prevent any negative impact of weather conditions and theft of assets stored within the containers.

Additionally, the doors feature a locking mechanism known mostly to container users. For new users, it may be necessary to consider familiarizing yourself with the cargo doors to learn to open them.

6. CSC Plate

The International Convention for Safe Containers (CFC) is a set of standards that govern the design of shipping containers. The convention protects human life by ensuring the containers are safe from structural failure.

For instance, for a shipping container to accommodate large cargo that’s several thousand pounds heavy, the loaders have to stack high cargo units. This comes with risks because the stacks can collapse, resulting in accidents to the workers at the port.

To prevent such catastrophic incidences, a qualified inspector must examine the container before the ship starts the journey to confirm that it’s safe to ferry the cargo. The inspector will then affix a CSC Plate to the container to certify that it’s safe.

7. Falcon Plate

A falcon plate is similar to CSC Plate, except that it’s unique to Falcon Structures. Falcon Structures are manufacturers of shipping containers.

They have their standards for modified containers where they inspect them to ensure they’re cargo-worthy and safe.

8. Marine-Grade Plywood Flooring

plywood flooring

Marine-grade plywood flooring is the most common type of flooring that comes with shipping containers.

To prevent pests and insects from penetrating the container, container manufacturers infuse small quantities of insecticides into the container’s flooring.

And you don’t need to worry about the insecticides aerosolizing and affecting you because they only eliminate the six-legged hungry stowaways trying to join your container’s journey.

9. Bamboo Flooring

In recent times, manufacturers are shifting from marine plywood flooring to bamboo flooring. That’s because of bamboo flooring’s affordability and availability.

Additionally, bamboo comes with its fair share of benefits. For example, it’s long-lasting and mildew-resistant. What’s more, bamboo is readily available as it’s a renewable resource.

Remember, bamboo also has a higher aesthetic value than plywood. This quality can be vital, especially in shipping container applications that include office and home spaces.

How Shipping Containers Are Made – Manufacturing Process

The manufacturing process of shipping containers involves the following steps:

  • First, the cutting of several steel sheets from one large roll. Factories employ technically advanced machinery systems to cut these sheets.
  • The sheets are sandblasted and primed to remove dirt, dust, debris, and contaminants as a means of surface preparation.
  • Corrugating of sheets is done to improve their overall strength.
  • Roof panels and floor braces are made separately. Also, wall panel sheets are welded together.
  • Fusing square tubing on the top of the walls.
  • Floor panels are assembled, forming a floor frame.
  • Once this is done, preparation of corner post assembly and door assembly is done separately.
  • The installation of door assembly follows and wall panels.
  • Wall panels, door assembly, and corner posts are welded together.
  • What follows is the assembling and welding of the roof panel.
  • At this point, priming and painting are done.
  • Then, wood frames with varnish are prepared for flooring.
  • Once fixing of the floor panels to the container floor is completed, holes are drilled in them
  • The door hardware is installed. Rubber seals are included to ensure the doors are watertight.
  • Lastly, the container bottom is waterproofed and tested for water tightness

Now the container is complete. What’s left is to inspect the container and ensure water tightness and also correct any other error.


steel shipping containers

The role that shipping containers play in global trading, shipping activities, and logistics is pretty dominant. With global trading activities consistently rising, shipping container production can only increase.

The simplicity of the structures makes them easy to modify. This explains why people are converting them into highly functional working, job site storage, and living spaces in recent times. They’re easy to install, flexible, and highly customizable. You can even modify a container to include windows and doors, lighting, and climate control.


Below are some frequently asked questions about shipping containers:

How Much Does a New Container Cost?

The cost of a shipping container is not standard. It differs based on one’s location. That said, a brand new 20-foot container may cost you around $4000 to $4500.

Which Is the Largest Shipping Container Manufacturing Country?

China is the leading container-producing country in the world. Surprisingly, of the total world shipping container production, China represents over 85%. China also boasts of being home to some of the largest shipping container manufacturing companies.

Are There Any Made-in-USA Shipping Containers?

Oh, yes. The USA has several shipping container manufacturers. These include Maersk, Hapag-Lloyd, COSTCO, American President Lines (APL), Evergreen Marine Corporation, and NYK Line.

Which Is the Largest Shipping Container Company?

Evergreen Marine Corporation is the largest container shipping company in the world. It’s based in Taiwan.

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