What Is The Thickness of Aluminum Sheets for Trailer

In the logistics and special operations sectors, lightweight upgrades for trailers have become an industry trend. Aluminum sheets, with their advantages of light weight, corrosion resistance, and high strength, are gradually replacing traditional steel as the core material in trailer manufacturing.

There are mainly three kinds of trailers using aluminum sheets:

Freight trailers: including semi-trailer truck and flatbed freight trailers. These trailers are exposed to the outdoors for extended periods and frequently need to withstand the corrosion of rainwater and road salt. The corrosion-resistant properties of aluminum plates can significantly reduce later maintenance costs.

Special-purpose trailers: such as refrigerated trailers and hazardous materials transport trailers. Refrigerated trailers require the lightweight aluminium plate for tankers with excellent insulation properties, typically using an insulation layer. Hazardous materials trailers have even higher requirements for the sealing and impact resistance of the aluminum sheets to prevent safety hazards caused by material aging.

Engineering and agricultural trailers: Such as engineering machinery transport trailers and agricultural grain transport trailers. These trailers need to withstand intermittent heavy loads or bumpy road conditions, so the aluminum sheet must balance strength and toughness to prevent deformation during loading and unloading of heavy loads or driving on rough roads.

Alloy selection

Different trailers have significantly different performance requirements for aluminum sheets, and the alloy composition directly determines the strength, corrosion resistance, and machinability of the aluminum sheet. Currently, the two most commonly used aluminum sheet alloys in trailer manufacturing are:

5000 aluminum alloys: 5-series alloys, with magnesium as the main alloying element, possess excellent corrosion resistance—especially in marine climates or high-salinity highway environments, where their rust resistance far exceeds that of ordinary steel.

Simultaneously, their elongation can reach over 20%, facilitating the processing into complex structures such as curved and folded edges, making them suitable for manufacturing trailer side panels and roofs.

Among them, 5083 alloy has higher tensile strength (approximately 310 MPa) and is often used for trailer flooring with high load-bearing requirements; 5052 alloy focuses more on lightweight and shaping, suitable for non-load-bearing parts.

6000 aluminum alloys: Some trailers with extremely high strength requirements (such as heavy machinery transport trailers) will use 6-series alloys. This alloy primarily uses magnesium and silicon, and after aging treatment, its tensile strength can reach over 370MPa, and its hardness is about 1.5 times that of 5-series alloys.

However, its corrosion resistance is slightly inferior to 5-series, and it is more difficult to process. It is usually only used for the load-bearing frame or connectors of trailers, rather than large-area panels.

Aluminum plate thickness

The aluminum sheet thickness for trailers needs to be determined based on the functional requirements of specific parts. Thicker isn't always better. Excessive thickness increases vehicle weight, reducing transport efficiency; insufficient thickness, on the other hand, can lead to structural deformation.

Panels (side panels, roof panels): They are Typically made of 1.5-3.0mm thick aluminum sheets. For ordinary freight trailers, side panels are often 2mm aluminium sheet, meeting wind pressure and minor collision requirements while controlling weight. Refrigerated trailer roof panels, needing to support the insulation layer, are typically made of 2.5-3.0mm thick 5083 alloy for enhanced support.

Flooring: As the core load-bearing component of the trailer, the thickness needs to be significantly increased, generally 4.0-8.0mm. Light-duty cargo trailers (load capacity ≤ 10 tons) can use 4mm aluminium plate; heavy-duty trailers (load capacity 10-30 tons) require 6.0-8.0mm thick 5083 or 6061 alloy, and some even have reinforcement on the back to further improve compressive strength.

Frame and connectors: The longitudinal beams and cross beams of the trailer, are mostly made of 5.0-10.0mm thick 6061 alloy to ensure the stability of the overall structure.