Steel Swing Arms vs Aluminum Swing Arms: Better or Preference?

Mountain Tarp, Donovan and Shur-Co Aluminum Swing Arm
It’s amazing that it took me this long to write a blog on Steel Swing Arms vs Aluminum Swing Arm Tarp Systems as I actually ask this question of my customers with virtually every Swing Arm System…”Do you want steel or aluminum arms?” After which I am usually asked “which is better? what’s the difference or benefit?”. Let’s take a deep dive into the Steel vs Aluminum Swing Arm debate!
Before we get too far along, it’s important to note that both Steel and Aluminum Swing Arm tarp Systems are used on a wide variety of trucks and trailers. This includes: Dump Trucks, Dump Trailers, Belly Dumps, Walking Floor Trailers and Roll-Off Trucks just to name a few. For the purposes of this blog, I’m taking Roll-Off Truck applications out of the equation and I will draft a separate blog focusing on this same topic for the Roll-Off Systems.
Ok, here we go…

Donovan Hammer Tarp System with Steel Swing Arms. Arms have been painted to match the color of the truck
Steel Swing Arms:
Generally speaking, I think we would all agree that steel is stronger than aluminum. So immediately, we have an apparent advantage for steel over aluminum. Likewise, steel is usually easier to repair. Meaning many end users have the capability of welding or repairing steel, while not quite as capable with aluminum. So right out of the gates, we have two potential advantages for steel! But wait, while these “advantages” appear to make steel the better option, let’s take a closer look. Yes, steel is stronger, but it is also heavier, which means steel arms are limited to about 28’ in maximum body length. While a 28’ flip tarp system will cover most dump trucks, it won’t be enough length to cover longer trailers. Also, steel will potentially rust and diminish the appearance of your tarp system. Aesthetics may or may not be an important aspect to you, but it must be stated.
Aluminum Swing Arms:

Roll-Rite Aluminum Upper Swing Arm for all Roll-Rite Tarp Systems
Aluminum Swing arms are obviously not quite as strong as steel however, most manufacturers have arms that are extruded to a very specific shape to provide strength and durability. A few manufacturers offer a “no break guarantee”. Meaning if you “break” the arm they will replace it at no cost (only shipping). Please remember that is a “no break”, not a “no bend” guarantee. Because aluminum swing arm tarp systems are much lighter than steel, they can be used on trailers up to about 53’ long! Likewise, aluminum swing arms will not rust and tend to have a better appearance over a longer period of time than their steel counterpart. Although the aluminum arms will not rust, it’s important to remember that some of the components, such as springs and mounting brackets are made of steel and may become prone to rust over time.
Dump Bodies and Trailers Under 28’ Long…
I find that drivers and owners who are looking to purchase a new tarp system often suggest to me that they want the “strongest” arms. My response is always the same. I say “both steel and aluminum arms are pretty strong, but if you put those arms in a battle with a Bobcat, Bucket-Loader or low hanging tree limb, I don’t care which one you have the arms will lose the battle”. Steel or Aluminum? Really a personal preference. Steel is stronger and possibly easier to fix. Aluminum is lighter and more attractive.
Dump Bodies and Trailers over 28’ Long…

Aero Model 595 Flip Tarp System with Aluminum Arms
If you have a dump body, dump trailer or walking floor trailer that is over 28’ long and you desire a flip tarp system with swing arms, then your only choice will be aluminum swing arms. This of course makes the choice very easy. Aluminum it is! Long arm swing tarp system have a variety of arm and spring configurations. Depending on the exact length of the trailer, the system may require a second “helper” arm and spring to assist in moving the long arms from front to rear.
Conclusion:
I really don’t give Steel or Aluminum the nod as one being better than the other. Functionality wise they are nearly identical. If you take care of your tarp system and avoid damage from other heavy equipment, falling loads or low hanging tree limbs you should experience many years of trouble-free operation from you tarp system.
Still not sure and need more information for swing arm tarp systems Give me a call at 757-615-4379 and we can talk about what system may be a better fit for your application.