How 4130 and 4340 Aircraft Quality Steels Make Superior Racing Frames
November 1, 2012 -
Not all types of steel are sufficiently strong, durable and lightweight to be worthy of the "aircraft quality" moniker. After all, aerospace companies can't risk incorporating sub-par alloys into the airframes that ferry millions of air passengers around the globe each year. Fortunately, the AISI aircraft quality 4130 and 4340 steels used by some of the world's biggest aircraft manufacturers do deserve this designation.
These two highly sought-after varieties of steel are used in other high-performance settings as well. For instance, the off-road racing industry is an important consumer of aircraft quality steel.
Off-road utility vehicles can race for long distances across uneven terrain littered with obstacles like rocks and stumps. It's not feasible to load them up with flimsy aluminum frames and stock suspension components. They require durable, compact suspension equipment that can stand up to whatever the trail has to offer. In other words, they require components forged from aircraft quality steel.
4130 steel is especially useful in utility vehicles' trailing arms. Since these devices connect the rear wheels to the rear axle at a slight downward angle, they often serve to limit vehicle clearance. In order to provide the necessary strength and support, stock trailing arms made from non-aircraft quality alloys must hang down from their vehicles' frames. One strike on a stray rock or ditch could cause a catastrophic suspension failure.
By contrast, heavy-duty yet compact trailing arms made from 4130 steel typically sit nearly three inches higher than stock arms. They also weigh up to eight pounds less. Utility vehicles that use corrosion-resistant 4130 trailing arms are safer and faster than their stock-suspension counterparts.
Meanwhile, 4340 steel is an integral component of any race-ready utility vehicle's axle. A utility axle must support bigger wheels than its on-road counterpart while also withstanding bigger bumps and jolts. A rear axle made from aircraft quality 4340 steel can be dozens of pounds lighter than a stock axle without sacrificing an ounce of strength. Utility vehicles that sport this equipment are astonishingly fast and sure-footed on the open track.
Aircraft pilots and utility vehicle drivers alike rely on aircraft quality steel to keep them safe while maximizing their performance. It's a good thing that the material on which they depend is far stronger than aluminum and has much better resistance to fatigue than traditional steel alloys.