There’s a long-standing rivalry between devotees of drop-side steel trays and aluminium trays. Fact is, both have positives and negatives depending on what tasks they are expected to perform and the environments in which they operate.
So if you’re contemplating purchase of say a cab-chassis one tonner and are undecided on whether a steel or aluminium tray would be best suited to your needs, here’s a few things to think about.
Weight
A HiLux steel tray weighs 308kg, which is 148kg more than a heavy-duty aluminium version.
Aluminium is much lighter than mild steel. As a general guide, a steel tray is about twice the weight of an equivalent aluminium tray. For example, in comparing HiLux trays from Toyota’s genuine accessories range, a heavy-duty aluminium tray weighs 160kg compared to 308kg for its steel equivalent. That’s a weight rise of 148kg or more than 90 per cent.
The negative effects of such a substantial increase go beyond any upsurge in fuel consumption and mechanical/tyre wear. The weight of a tray must also be added to a vehicle’s kerb weight, which reduces its GVM (Gross Vehicle Mass) rating and, as a result, its payload.
For example, if a light commercial vehicle in cab-chassis form has a kerb weight of 1500kg and GVM of 2800kg, that means it has a 1300kg or 1.3 tonne payload capacity. However, when you add a steel tray which weighs 300kg, the payload has to be reduced by the same amount to avoid exceeding the GVM. So, the heavier the tray, the smaller the payload. Therefore, the much lighter kerb weight achieved with an aluminium tray can be a great advantage if payload capacity is important.
However, the extra weight of a steel tray can also be useful too, particularly in cab-chassis vehicles often driven unladen or with light loads. Their leaf-spring rear suspensions, usually designed to carry one tonne-plus payloads, can be so stiff without a decent load over them that they’ll try to punch your head through the roof each time you drive over any bump larger than a pebble.
Fitting a heavy steel tray, though, can often provide the sprung weight needed to compress those rear springs enough to improve ride quality when empty.
Strength
A steel tray is well suited to a Tradie's lifestyle.
As a general guide, steel can be up to four times stronger and three times stiffer than aluminium. So, where strength and hardness are most important for your work application, steel stands out as the obvious choice.
However, that’s not to say that heavy-duty aluminium trays don’t offer ample strength and rigidity. There are plenty of owners more than happy with the performance of their aluminium trays in harsh environments; it just depends on your specific work requirements.
For example, given that aluminium is softer than steel, you don’t need to be a metallurgist to know an aluminium tray is going to come off second-best in any repeated clashes between the two. So if your work involves carting around lots of heavy steel Acrow props, jackhammer drill bits, star pickets, sledgehammers etc that are usually thrown aboard rather than carefully placed (and let’s face it, who does that?) a steel tray could be better suited to such abuse.
Steel could also be a better choice for carting landscape supplies, particularly piles of hard jagged rocks which can tumble with great force from the bucket of a front-end loader. However, the extra weight of the steel tray will also reduce the amount you can carry, so this always has to be factored in.
Corrosion
A mild steel tray will start to rust almost immediately when exposed to the great outdoors if not sealed in some form.
In addition to its lighter weight, aluminium’s other great advantage is corrosion resistance. Aluminium is made from bauxite, but mild steel is made from alloys of iron and carbon. Therefore, aluminium is non-ferrous and rust-free, whereas steel is the direct opposite.
Therefore, you don’t need to protect an aluminium tray from the elements. It’s particularly good in coastal environments, where exposure to sea air and (depending on your usage) salt water will not result in the dreaded rust taking hold.
Mild steel, on the other hand, if not sealed in some way will start to rust almost immediately when exposed to the great outdoors. And salt water is its greatest enemy. Arguably the most effective treatment to prevent this is hot-dip galvanising, but other options can include powder-coating or at least a decent lick of paint.
Regardless of which protective treatment is chosen, the chips and scratches that inevitably result from hard use will always lurk as potential rust starters. The good news is that steel used in the construction of tray bodies is generally much thicker than the lightweight sheet-metal used in the production of automotive bodies.
So, unless you drive rather than dive into the surf each morning, even a poorly maintained steel tray is unlikely to suffer the depth of rust that can compromise its structural integrity, even after years of hard work.
Cost
Aluminium custom-made trays usually cost more than ones made of mild steel.
Aluminium is around 30 per cent more expensive than mild steel, so you would expect an aluminium tray to cost that much more as a result. That’s usually the case with custom-made trays, given the higher cost of raw materials, specialised MIG/TIG welding gases and labour due to longer fabrication times.
However, this price difference is not consistent across pre-fabricated trays, which are typically the preferred option for car dealers. These trays are usually delivered in flat-pack kit form and bolted together by the dealerships as drive-away-no-more-to-pay packages, but in some cases flat-pack steel trays can cost more depending on their design and shipping costs.
Although these one-size-fits-all trays aren’t tailored to suit specific requirements like a custom-made tray, they are roughly half the price and, in many cases, more than adequate for the work expected of them.
Other considerations
Both steel and aluminium trays can be modified or custom-made to suit specific work requirements.
Steel is magnetic and aluminium is not, which could be either helpful or hazardous depending on your job requirements. Steel can also create sparks in some situations, which could tip the safety balance in favour of (non-ferrous) aluminium if flammable gases or liquids are commonly found in your workplace.
If building a custom tray, thought should also be given to the drop-sides and how they could be removed to double as ramps for loading wheeled machinery if required. Reinforced aluminium ramps could be adequate, or the greater strength and rigidity of steel could be required. However, the latter would also be much heavier, which could present a weighty problem when removing and replacing from the sides of the tray.
Also consider what equipment may be required for your work application, particularly if the tray is going to have a hydraulic tipper function or perhaps you’re planning to mount a small crane for loading heavy items. Some of these calculations may require the input of a certified engineer to advise if an aluminium or steel tray is the best option.
Some ute owners may also want a tray to match the colour of their vehicle’s cab, either for commercial reasons (like fleets with uniform colour and signage requirements for each vehicle) or a tradie just wanting a more integrated look for his or her work vehicle. This is more easily achieved with a steel tray.
Conclusion
These are just some of the key factors which should be considered. The best advice, though, is to go to the coalface. Ask vehicle owners in your line of work why they chose a steel or aluminium tray, whether it suits their needs and what (if any) shortcomings they’ve found in the field. That way, you’re almost guaranteed to make the right decision first time.
