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Shipping Container Terms to Know

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Shipping containers have become common in our modern world, from construction sites and ports to portable offices, modular buildings and more. However, for those unfamiliar, shipping container terminology and jargon can be confusing and overwhelming. In this article, we’ll take a closer look at some of the shipping container terminology you need to know to understand the language of shipping containers.

13 Shipping Container Terms to Know

Whether you’re a business owner looking to ship your products overseas or simply curious about how these massive steel boxes work, we’ve got you covered. This guide will give you the knowledge you need to navigate the world of shipping container terminology.

The standard shipping container is 8’ 6” tall, and the most common container sizes are 20 and 40 feet long. They’re created out of Corten steel, a type of weathering steel resistant to weather effects. Typical containers have double cargo doors on one end and an end frame on the other.

This diagram highlights the most common shipping container terminology.
Here are a few of the most common shipping container terms that can be helpful when buying, renting or modifying a container.

1. Door Header

A door header is an integral part of the container’s structure. It’s a horizontal beam that runs along the top of the cargo doors, adding support for the roof, distributing storage weight and strengthening the security of the doors to the container. For modified containers that add roll-up doors, the plate protects the roll-up door barrel.

2. Door Gasket

Seals called gaskets are installed around the cargo doors to prevent moisture, dust, and other contaminants from entering the container’s storage space. You can lodge these gaskets in channels and grooves around the perimeter of the door frame. They’re also a crucial part of the container’s wind and weather-tight qualities.

3. Lock Box

Here at Southwest Mobile Storage, we use a three-tiered system to make sure our containers offer vault-level security. Lock boxes are a critical security feature we install on shipping containers that prevent unauthorized access to stored materials.

When a padlock is enclosed in a steel lock box, it becomes much more difficult to successfully gain access inside a container. Moreover, potential thieves must use cutting or drilling, deterring criminals that don’t have the time or energy to deal with the challenge.

Graphic showcasing different shipping container terminology. It shows a door gasket, a door header, and a lock box.

4. Slide Bolt

The second part of our container security system is our slide bolt. When closed, a heavy-duty puck lock can be attached to the circular spot inside the slid bolt frame, creating another layer of security to deter break-ins.

5. Door Locking Handle

Our container security system’s third step is the door-locking handle. The handles aid in opening and closing the doors and have the capability to lock in their final resting place, situated beneath the container locking tabs. The locking tabs are lockable with padlocks, thus providing a final seal for container security.

6. Door Panel

The door panel of a container allows access to the inside of your container and holds the other components attached to the door, like locking bars. Each door is made of thick steel and can swing 270 degrees outward.

Graphic showcasing different shipping container terminology. It shows a door panel, a slide bolt and a door locking handle.

7. Locking Bars

The locking bars span the width of the container’s door opening and attach to the end frame on each side of the door. Handles located on the exterior of the container typically operate the locking bars, which rods or cables connect to.

The door-locking handles secure the locking bars in place, holding the doors securely closed and preventing them from opening during transportation. Two locking bars are standard in 20-foot containers, while larger 40-foot containers may have four or more.

8. Forklift Pockets

One of the biggest benefits of using a container for storage is that you can easily transport it. You can transport containers by forklift using the two pockets on the bottom sides of the container. From here, you can transport them on-site or onto a truck bed for delivery to a location farther away.

9. Corner Casting

Corner castings serve an essential role in maintaining your container’s structure. These eight 3.0mm thick corner castings have some of the thickest steel on the container, allowing containers to be stacked and handled securely. You can stack a maximum of nine containers, but this limit may be lower depending on local conditions.

Graphic showcasing different shipping container terminology. It shows locking bars, forklift pockets and corner castings.

10. Top Side Rail

The top side rail of a container helps provide structure to the roof. That helps distribute weight evenly across the top of the container. It also ensures a level surface that prevents stacked containers from shifting during transportation.

11. Side Panel

The corner posts, top rails, and bottom rails work together with container side panels to create a rigid frame that distributes weight. Corrugated side panels, which have distinctive ridges and grooves add strength and flexibility. These panels enclose the storage area and prevent stored materials from moving around when properly stored.

12. End Frame

A container end frame is a structural component of a shipping container located at the end of the container. Thus, the rectangular frame made of steel provides stability to the back of the container.

13. Bottom Rails

The bottom side rail performs a crucial function in holding up the rest of the container, acting as the primary load-bearing component of the container. It connects to the bottom corner castings to lock on to containers beneath.

Graphic showcasing different shipping container terminology. It shows a top side rail, a side panel and an end frame.


After this list, you should better understand shipping container terminology and how the different parts of a container work together to provide you with secure storage space. Moreover, knowing what container parts do can give you the confidence to undertake repair projects or inspire you to modify a container for a specific use.

Related Blogs

If you’re interested in learning more about shipping containers and the terminology associated with them, we have several helpful blog posts that can help you deepen your understanding. Some popular topics include container sizes, types, and uses, as well as shipping container modifications and creative reuse ideas. Other posts may cover topics such as best practices for container shipping and handling, and container design and modification. Click on a link below for more insights!

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