Choosing the right metal for trailer sides affects durability, weight, and maintenance. We researched manufacturer specifications, industry standards, and aggregated owner feedback to compare the top materials. This guide evaluates steel, aluminum, and specialty alloys for strength, corrosion resistance, and ease of fabrication.
Each pick is assessed on performance, durability, value, ease of use, and safety. We highlight real limitations so you can decide which metal suits your trailer type and usage.
| Photo | Product | Score | Buy |
|---|---|---|---|
|
🚗
|
Aluminum 5052-H32 Sheet Best Overall 0.063 to 0.125 inch thickness, 5052-H32 temper, good formability |
9.0 | 🛒 Check Price |
|
🚗
|
Steel Sheet A36 Hot Rolled Best Strength 0.0747 to 0.1345 inch thickness, 36 ksi yield strength |
8.7 | 🛒 Check Price |
|
🚗
|
Aluminum 6061-T6 Sheet Best Lightweight Strength 0.063 to 0.190 inch thickness, 40 ksi tensile strength |
8.4 | 🛒 Check Price |
|
🚗
|
Galvanized Steel Sheet G90 Best Corrosion Resistance Steel 0.036 to 0.0747 inch thickness, G90 zinc coating |
8.1 | 🛒 Check Price |
|
🚗
|
Stainless Steel 304 Sheet Best For Marine Use 0.048 to 0.125 inch thickness, 304 alloy, 2B finish |
7.8 | 🛒 Check Price |
|
🚗
|
Aluminum 3003-H14 Sheet Best For Light Duty 0.032 to 0.080 inch thickness, 3003-H14 temper, moderate strength |
7.5 | 🛒 Check Price |
|
🚗
|
Expanded Metal Mesh (Steel) Best For Ventilation 0.75 to 1.5 inch diamond opening, 14 to 16 gauge steel |
7.3 | 🛒 Check Price |
1. Aluminum 5052-H32 Sheet: Best Overall
5052-H32 aluminum is a top choice for trailer sides due to its balance of strength, formability, and corrosion resistance. In our evaluation of spec sheets and owner feedback, this alloy consistently performs well in utility and boat trailers where moisture exposure is high. It is lighter than steel, which helps improve fuel economy and handling, and it can be easily fabricated with standard tools. However, its yield strength is lower than some other aluminum grades, so it may not be ideal for heavy-duty commercial trailers that carry dense loads.
Owners report that 5052-H32 holds up well over years of outdoor storage, but it is more prone to scratching and denting than steel. Skip this if you need maximum impact resistance or plan to haul abrasive materials that could gouge the surface.
- Excellent corrosion resistance for marine or wet environments
- Lightweight compared to steel, reducing trailer gross weight
- Easy to cut, drill, and weld with common tools
Pros: High resistance to rust and salt spray; Readily available in various gauges
Cons: Lower tensile strength than 6061-T6, may dent under heavy loads
2. Steel Sheet A36 Hot Rolled: Best Strength
A36 hot-rolled steel is the workhorse for heavy-duty trailer sides. Based on manufacturer data and owner reports from farm and construction trailers, it offers unmatched strength and resistance to denting under rough loading. It is also the most economical option per pound. However, its weight significantly reduces the trailer’s payload capacity and can strain the tow vehicle. Without proper coating, A36 steel rusts quickly in humid or salty conditions.
This material is best for trailers that stay on pavement or are frequently repainted. Skip it if you need corrosion resistance without maintenance or if weight is a primary concern for your towing setup.
- Very high strength and impact resistance for heavy loads
- Low cost per pound compared to aluminum
- Readily weldable with common arc welding equipment
Pros: Extremely durable and dent-resistant; Easy to repair with welding
Cons: Heavy, reducing payload capacity and increasing fuel consumption; Prone to rust if not painted or galvanized
3. Aluminum 6061-T6 Sheet: Best Lightweight Strength
6061-T6 aluminum is a premium choice for trailer sides that need to be both strong and light. In our comparison of spec sheets, it offers nearly twice the yield strength of 5052-H32, making it suitable for side panels that also serve as structural supports. Owner feedback from custom trailer builders highlights its excellent machinability and weldability. However, it is less corrosion-resistant than 5052 in marine environments and requires care during forming to avoid stress cracking.
This material is ideal for enclosed cargo trailers or flatbeds where weight savings justify the higher cost. Skip it if you need maximum corrosion resistance for a boat trailer or if you plan extensive bending without annealing.
- Higher strength-to-weight ratio than 5052, ideal for structural sides
- Good corrosion resistance, though less than 5052 in saltwater
- Machines and welds well with proper technique
Pros: Stronger than 5052, resists bending under load; Lighter than steel for same strength
Cons: Less formable, may crack if bent too sharply; More expensive than 5052 and steel
4. Galvanized Steel Sheet G90: Best Corrosion Resistance Steel
Galvanized steel G90 offers the strength of steel with built-in corrosion resistance. Based on industry standards and owner reviews, it is a popular choice for utility trailers used in winter climates where road salt is prevalent. The zinc coating protects the steel from rust even if scratched, though welding or cutting exposes bare metal that must be repaired. It is heavier than aluminum and costs more than uncoated steel, but saves on maintenance over time.
This material is best for trailers that see harsh weather and where weight is not the primary concern. Skip it if you need to weld extensively without coating reapplication or if maximum weight savings are critical.
- Zinc coating provides long-lasting rust protection
- Strong and impact-resistant like standard steel
- Available in lighter gauges to reduce weight
Pros: No need for painting if coating remains intact; Good for trailers exposed to road salt
Cons: Welding damages the coating, requiring touch-up; Heavier than aluminum and more expensive than bare steel
5. Stainless Steel 304 Sheet: Best For Marine Use
304 stainless steel is the premium choice for trailer sides in corrosive environments like boat launching or livestock hauling where sanitation matters. In our evaluation of material data sheets, it offers exceptional durability and a long lifespan with minimal maintenance. However, it is the heaviest and most expensive option, and fabrication requires carbide tooling and careful welding to avoid carbide precipitation. Owner feedback indicates that the high cost is only justified for specialized applications.
This material is best for marine trailers or food-grade trailers where corrosion resistance is paramount. Skip it for general utility trailers where budget and weight are more important.
- Excellent corrosion resistance in saltwater and chemicals
- High strength and impact resistance
- Non-reactive, safe for food-grade trailers
Pros: Virtually rust-proof in most environments; Stainless look requires no painting
Cons: Very expensive and heavy compared to aluminum; Difficult to cut and weld without specialized tools
6. Aluminum 3003-H14 Sheet: Best For Light Duty
3003-H14 aluminum is the budget-friendly choice for light-duty trailer sides such as small utility trailers or DIY campers. Spec sheets show it has about half the tensile strength of 5052, but it is very easy to work with and resists corrosion well. Owner feedback from hobbyists praises its formability and low cost. However, it is not strong enough for heavy loads and will dent or bend if used for cargo that shifts.
This material is best for lightweight trailers that carry soft goods or for decorative side panels. Skip it if you need to haul dense materials or require structural rigidity.
- Very affordable and widely available
- Excellent formability for bending and shaping
- Lightweight and easy to cut with hand tools
Pros: Lowest cost aluminum option; Great for DIY projects with limited tools
Cons: Low strength, dents easily under load; Not suitable for heavy-duty or structural sides
7. Expanded Metal Mesh (Steel): Best For Ventilation
Expanded metal mesh is a practical alternative for trailer sides where ventilation or visibility is needed, such as landscape trailers or utility trailers hauling brush. Based on manufacturer specs and owner reviews, it provides good strength with reduced weight compared to solid sheet. The diamond pattern allows air to pass through, reducing wind drag and improving fuel economy. However, it does not protect cargo from rain or theft, and the cut edges can be sharp if not finished.
This material is best for open trailers carrying lightweight, bulky items. Skip it if you need enclosed sides for security or weather protection.
- Allows airflow and visibility while containing cargo
- Strong and durable for containing loose items
- Lightweight compared to solid sheet of same thickness
Pros: Reduces wind resistance on open trailers; Prevents debris from falling out
Cons: Not weatherproof; cargo exposed to elements; Sharp edges if not properly deburred
Frequently Asked Questions
What is the best metal for trailer sides in a saltwater environment?
For saltwater environments, aluminum 5052-H32 or stainless steel 304 are the best choices due to their high corrosion resistance. 5052-H32 offers a good balance of cost and performance, while 304 stainless is more durable but significantly more expensive and heavier. Avoid bare steel unless it is galvanized and maintained.
Is aluminum or steel stronger for trailer sides?
Steel, such as A36, has a higher yield strength than most aluminum alloys, making it more resistant to denting and bending under heavy loads. However, aluminum 6061-T6 approaches steel strength at a lower weight. For identical thickness, steel is stronger, but aluminum can be used in thicker gauges to achieve comparable strength while saving weight.
How do I prevent rust on steel trailer sides?
To prevent rust, use galvanized steel (G90) or apply a high-quality paint or powder coating after fabrication. Regular maintenance, including washing off road salt and touching up scratches, extends the life. Alternatively, choose aluminum or stainless steel for inherent corrosion resistance.
Can I weld aluminum trailer sides with a standard MIG welder?
Yes, but you need a spool gun or push-pull system for aluminum wire, and the welder must have enough amperage. 5052 and 6061 aluminum are weldable with 5356 filler wire. However, welding aluminum requires more skill than steel, and proper cleaning is essential to avoid porosity.
What thickness of metal is recommended for trailer sides?
For steel, 0.0747 to 0.1345 inch (14 to 10 gauge) is common for utility trailers. For aluminum, 0.063 to 0.125 inch (1/16 to 1/8 inch) works well. Thicker material adds strength and dent resistance but increases weight. Choose based on the trailer’s intended load and weight capacity.
Our Verdict
Our top pick is Aluminum 5052-H32 for its excellent corrosion resistance, light weight, and ease of fabrication, making it suitable for most trailer types. The runner-up is A36 hot-rolled steel for maximum strength and durability at a lower cost, ideal for heavy-duty applications where weight is not a primary concern.
Last reviewed and spec-checked: May 13, 2026. We re-check our picks and listings periodically.
