A rod end bearing is a common type of mechanical joint used on the ends of control rods. The steering columns in most cars, trucks and other vehicles, for example, feature tie rods with a rod end bearing. Of course, tie rods are designed to connect a vehicle’s steering rack to its steering knuckle. As a result, tie rods must be able to rotate according to the direction in which the wheel is turned. Rod end bearings allow tie rods to perform this rotation in a precise and controlled manner. To learn more about rod end bearings and how they work, keep reading. If you’re looking to purchase Rod Ends, Monroe has you covered.
Rod End Bearings Explained
Also known as a heim joint in the United States or a rose joint in the United Kingdom, a rod end bearing is a mechanical joint that features a rounded ball-like swiveling tip. They were invented in Germany during the 1930s to 40s for use in aircraft control systems. This promoted a company called H.G. Heim Company to patent and produce its own rod end bearings in North America, which is why the mechanical joint now has the moniker “heim joint.”
H.G. Heim Company has since closed its doors for business, but rod end bearings are still produced and used throughout the world. Automotive tie rods are just way in which rod end bearings are used. They are used in countless other applications in which an articulating joint is needed, including aircraft control systems, steering links, track rollers and more.
Rod end bearings are typically made using the following materials:
- Steel
- Stainless steel
- High-carbon steel
- Aluminum
Male vs Female Rod End Bearing: What’s the Difference?
A rod end bearing can be classified as either male or female depending on the way in which the threading is designed. Male rod end bearings are designed with external threading. In comparison, female rod end bearings are designed with internal threading. With interior threading, female rod end bearings can handle unique applications that aren’t possible with male rod ends bearings. Helicopters, for instance, often use female rod end bearings to adjust the direction of the blade. They allow pilots and aviation technicians to fine tune their blade adjustments.
You can see an example of both male and female rod end bearings in the photo above. The red rod end bearing is male because the threading is located on the exterior, whereas the black rod end bearing is female because the threading is concealed inside it.