When you’re shopping for a trailer, the big, easy numbers come to mind first, and those should be your first focus: GVWR, payload capacity, axle rating, trailer size, and steel thickness. But there’s a lot more detail you should pay attention to.
Another specification you must look for is on-center spacing, often called O.C.
You might see a trailer listed with 16″ O.C. floor crossmembers, 24″ O.C. floor crossmembers, or similar spacing for wall and roof members. But what do the numbers mean? Does a 16″ O.C. floor crossmember mean your trailer must be stronger than one with 24″ O.C. floor crossmembers?
Not necessarily. But the wider gap affects how the trailer’s structure is supported, and it increases the unsupported spans between members.
Let’s break down the difference.
16″ O.C.—What Is It?
When a trailer is specified with 16″ on-center spacing, that means that the structural members are spaced relatively closely together. For a trailer floor, that means more structural members support the deck because the cargo placed on the deck has more closely spaced structural support.
For a trailer wall, 16” means more wall members support the wall material along its length.
This type of construction can be desirable when the trailer will be used in more demanding working conditions, will experience frequent loading and unloading, or will encounter heavier, more concentrated loads. You also get a shorter unsupported span between members. The downside is that you will generally have more structural members and use more material, which can add weight.
24″ O.C. Spacing: What Does It Mean?
With 24-inch o.c., members are spaced further apart.
This extends the unsupported span from member to member. 24″ O.C. construction provides a viable structural system depending on the design, materials, and the intended use of the trailer.
Advantages may include fewer structural members, so you may use less material and reduce weight.
By keeping supports closer together, you can buttress the entire part more easily. However, the larger distance between supports means the decking or wall material has a greater span between structural members.
For example, you should always consider the distance between supports, the thickness and nature of the objects being supported, the size of the framing, and the trailer’s overall engineering.
16” vs. 24” O.C.: Side-by-Side Comparison
| Feature | 16” O.C. | 24” O.C. |
| Distance between members | 16 inches | 24 inches |
| Support frequency | More frequent | Less frequent |
| Unsupported span | Shorter | Longer |
| Floor support | More closely spaced | More widely spaced |
| Wall support | More closely spaced | More widely spaced |
| Potential for flex between supports | Generally lower | Generally greater |
| Structural members required | More | Fewer |
| Material use | Typically higher | Typically lower |
| Potential weight impact | May add weight | May reduce weight |
| Heavy-duty applications | Can provide an advantage | Can be suitable depending on design |
| Overall trailer strength | Depends on complete construction | Depends on complete construction |
When 24″ O.C. May Be Appropriate
There are cases when 24″ O.C. construction can make sense. A trailer designed to carry a specific load range and duty cycle doesn’t always need the same level of structural density as a trailer going into the most demanding commercial service.
Wider spacing can eliminate some members to save weight, which can matter to manufacturers balancing structural integrity with trailer weight, payload, and manufacturing costs.
The key is whether the complete trailer has been properly designed for its application. A trailer that is properly built to 24″ O.C. isn’t necessarily a trailer that is built like trash.
When 16″ O.C. is a better choice
For the power user, closer spacing can be a desirable touch.
Contractors, builders, landscapers, farmers, and other commercial users may encounter this when loads are unevenly distributed on the trailer floor.
Heavy loads can be concentrated in small areas, such as equipment, machinery, materials, and other cargo.
In these cases, closer structural elements can add support underneath the deck.
This principle also applies to trailer walls, especially if the trailer is used heavily.
In addition to offering buyers peace of mind and reliability, it is also a specification to look for if trailers will be used in challenging environments or applications.
Why Cynergy Is a Strong Choice
When prospective buyers evaluate construction features instead of price tags, they may take comfort in knowing these specifications are available from a particular manufacturer. Not every manufacturer is the same. Cynergy Cargo’s Advanced enclosed trailer models, for example, list 16″ O.C. floor crossmembers and 16″ O.C. wall members on specified models.
Some models also use tubular structural members in the floor, walls, and ceiling.
That way, potential buyers can see exactly how much closer together the structural members are placed in the design than they would otherwise be. Cynergy offers different construction models throughout the product line, so specifications aren’t necessarily universal from model to model. That’s important because prospective trailer buyers should get in the habit of comparing models rather than brand names. For Kinema Trailer Depot customers, this is one way Cynergy becomes an option worth considering whenever structural construction matters.
The Bottom Line
The differences between 16″ O.C. and 24″ O.C. come down to the support between structural elements and the open span between them.
16″ O.C. trailers have shorter unsupported spans and more structural members, whereas 24″ O.C. trailers have longer unsupported spans and fewer structural members. Either can be suitable based on what you want to do with the trailer.
Don’t just compare one spec when shopping for a trailer. Also compare the rest of the construction: steel gauge, member sizes, frame design, decking, axles, GVWR, and overall build quality.
Need some guidance? Talk to the staff at Kinema Trailer Depot of Douglas, GA. They will walk you through your options and pair you with a trailer that has the right combination of size, design, and capacity.
FAQs
What does 16″ O.C. mean on a trailer?
16″ O.C. means the center of a structural member is 16″ from the next adjacent one. That is usually closer than members spaced 24″ on center.
What do you mean by 24″ O.C. in a trailer?
24″ O.C. stands for “24 inches on center.” This is the distance between the centers of one structural member and the next. 24″ means there is a greater distance between each structural member.
Is 16″ O.C. stronger than 24″ O.C.?
The closer the supports are spaced, the better the deck is reinforced. The trailer’s strength depends on all components, including steel gauge, member size, frame design, and deck material.
Does 24″ O.C. make a trailer weak?
No. A properly designed trailer with 24″ O.C. can have a support spacing of 24″ O.C., which can be a very useful, as long as it is designed to be used at this spacing. Always consider the rest of the trailer’s build when you are deciding on this support spacing.
Why is deck spacing important?
The deck spacing is how often the decking is supported. The closer the supports are spaced, the shorter the unsupported span between the cross members.
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