How are Trailer Axles made?

by | Sep 23, 2020


At Duratek, we know that the little details can make all the difference. In the world of trailer axles, quality, safety, and dependability are essential in making sure your trailer is always operating at it’s best. That’s why Duratek uses a thorough, detailed process with quality checks at every stop alone the way. With this attention to detail, we make sure you can trust in what you’re towing.


The process begins with a square metal tube. The capacity of the axle defines the size and the wall thickness of the tube. The tube is then cut to the requested length and is bent into a slight arc for camber. The inner bar’s correct size is chosen and welded to a trailing arm and spindle assembly (known as a Z-Bar assembly); the inner bar end of the Z-Bar is placed into the inside of the tube. The corresponding sizes of rubber cords are placed in a liquid nitrogen cryogenic press. The compression and freezing make the rubber contract, so it can be put inside the square tube with the inner bar (the slugging process). When the rubber thaws and returns to room temperature, it expands slightly, pushing in against the inner bar and out against the outer tube. This compression acts as a cushion and is what provides the suspension in a torsion axle. After covering the axles in a special coating, hubs, brakes, etc. are fit the customer’s specifications.

Duratek uses a process similar to the one described to produce high-quality axles with short lead times!


The spring axle production process begins with a round tube. The round tube acts as the main portion of the axle. The tube length is cut, and holes are punched into it to run wiring. Next, the spring seats are welded onto the axles, and each axle gets loaded into an automated welding machine. In the end, each spindle is mounted on to a special fixture to ensure the alignment is correct. Then the axles are cambered, to ensure even tire wear when loaded and then dipped in a special coating. A special jig attaches the leaf springs, keeping the springs straight while being tightened down. Once the bolts are tightened, hubs, brakes, and other parts are added and fit to the customer’s specifications. 

Duratek uses a process similar to the one described to produce high-quality axles with short lead times!