Shipping container grades can sometimes be confusing to understand. Once a container is decertified from ocean freight shipping, the standards for evaluating them are not uniform across the industry. This can make it challenging to weigh your options when deciding which shipping container grades are ideal for you or your business. In this post, we discuss different types of shipping containers grades and how containers are categorized.
To understand shipping container grades, there are three things you must consider:
- The age of the container when we receive them.
- The grading of the container’s condition.
- The type of modification work we do.
Below, we break down these types of containers and provide information about how containers are classified.

Understanding Shipping Container Grades by Age
There are three types of shipping containers available in the United States, best defined by the amount of time they were used for ocean freight shipping:
- One-trip containers
- Cargo-worthy (CW) containers
- Wind and Weathertight (WWT) containers
One-Trip Containers
One-trip containers are the newest shipping containers available for sale in the United States. Companies overseas manufacture containers that are shipped across the ocean full of cargo. They make one cargo trip across the ocean before we add them to our inventory for sale or modification. One-trip containers have the following:
- Fresh paint
- Minor dents and scratches
- “Like new” flooring
- Export suitability
These shipping containers have been manufactured in the last two years. This makes them ideal for maintaining your business or home’s clean, polished appearance – especially if you place it within sight of your customers, visitors or neighbors.
Cargo-Worthy Containers
Most of the containers we rent, sell and modify don’t return to the open ocean. Unless they’re a one-trip container, they’ve likely served enough time on the waves already. Cargo-worthy containers have the possibility to be returned to shipping service with a valid shipping certificate.
To return to export use, an authorized inspector must verify the container is suitable for transporting cargo. You’ll need to consider this if you intend to ship freight with a container like this. These containers have the following:
- Faded paint
- Some dents, repairs and surface rust
- Export suitability (Shipping certification required)
- Flooring with some scratches, gouges and patches
Generally speaking, cargo-worthy containers are between 1 and 10 years old. Typically, you’ll only want to consider this container if you need one for exports. Otherwise, you’d be better served by a one-trip on the high end and might find better budget options with the subsequent shipping container classifications on our list.
Wind & Weathertight Containers
Wind and weathertight units have been decommissioned by the ports for cargo use and are typically older than 10 years. These containers guarantee that your stored items will be safe from rain and other weather. If you’re looking for a simple storage solution and a polished appearance isn’t crucial, a WWT container might be what you need. These units have:
- Faded paint
- Dents, repairs and surface rust
- Flooring with many scratches, gouges and patches
WWT containers offer an excellent middle ground. They maintain their structural integrity for smoother customization. However, modifying them may take longer in our shop as they require more repairs than other options.
If you need a polished look, you might prefer a one-trip or refurbished container. A wind and weathertight container will work fine if your priority is secure storage at an affordable price.
Shipping Container Grades (Condition)
While previous sections have discussed different container classifications, there’s still a fair amount of difference in the condition in each classification. Because of this, three shipping container grades give customers a general idea of how much wear a container has taken: Grade A, B and C. Each grade is based on how the container has held up in two key areas: the number of dents and scratches and the level of rusting on the container’s interior and exterior. These two factors can give you a general idea of the condition you can expect from shipping container grades.

Grade A
Grade A containers are the highest grade of container condition. With minor to medium dents, scratches and rusting, Grade A containers have minimal wear and tear. Minimal dents mean that there’s less space for rust to develop. A grade A container can continue to provide secure storage for years to come with regular maintenance.
- Very good general appearance
- Minor to medium dents & scratches
- Superficial rusting on exterior or interior
Grade B
Grade B containers sit in the middle of shipping container grades. They have more dents and rust but no heavy wear. Some one-trip containers can fall into this category if they’re roughed up on their sea journey.
- Good general appearance
- Minor to medium dents and scratches
- Minor to medium rusting on exterior or interior
Grade C
A Grade C container has endured heavy wear and tear. These containers can be great DIY projects or the start of a customization job. You won’t find a Grade C one-trip container because it’s unlikely that a container will take enough of a beating on its journey to be classified in this category.
- Mediocre general appearance
- Medium to heavy dents and scratches
- Medium to heavy rusting on exterior or interior
Shipping Container Grades and Modifications
At Southwest Mobile Storage, you can modify a one-trip, cargo-worthy or wind and weathertight container to fit your needs. Customizations range from your choice of paint on the outside to more elaborate upgrades inside the container. We can modify any container to add shelving, insulation, windows, electrical outlets and HVAC. If you can dream it, we can do it!
If you want to fabricate a shipping container, you’ll need to first decide which type of container you want to use. You can opt for a one-trip container that is newer, or you can select an as-is container or a refurbished container. Let’s take a look at the differences:
One-Trip Container Modifications
Because of their limited use, one-trips often require fewer repairs than an As-Is container. One-trip shipping containers maintain factory specifications; their corrugated steel isn’t bent or twisted. This makes them ideal candidates for modification. Their straight corrugation makes it easier to take measurements and make cuts, leading to more efficient fabrication.
As-Is Container Modifications
As-is containers are a catch-all category for used containers, and their condition will vary from seller to seller. Our as-is containers are still wind and weathertight. We leave these containers as they are. These containers have the following:
- Faded paint
- May have many dents, repairs and surface rust
- The flooring might have holes
- May needs repairs before modification
Buying an as-is container and restoring it might be practical if you’re familiar with repairing shipping containers. At Southwest Mobile Storage, we often refurbish as-is containers for use in customization projects. Giving new life to old cargo containers is a great way to expand your onsite storage space.
This category of containers is the most flexible and cost effective. Get an idea of what kind of as-is container you need. Talk to one of our experienced sales representatives today and schedule a time to look over potential container matches.
Refurbished Container Modifications
When we add used containers to our inventory, we upgrade some of them. This includes giving them a fresh coat of paint and making repairs. When our team of fabrication experts is done with these fixes, the result is a refurbished container. All of our rental containers are refurbished or one-trip units. These containers have the following:
- Fresh paint
- Some dents and repairs
- Flooring with minor scratches, gouges and patches
These containers spent years carrying cargo across the ocean, but have been decertified for cargo service. After refurbishment, they have less rust, structural damage and cosmetic flaws.
Containers that we refurbish are suitable for installation outside your business or home without looking out of place.
Finding Shipping Container Grades For You
Whether you’re looking to finding your first container or you’ve been down this path many times, Southwest Mobile Storage is here to help you compare shipping container grades to find the right fit for you.
Whether you need a one-trip, wind and weathertight, or an as-is container, we’ve got every angle covered. Get a quote from us about your cargo container today!