Rod end bearings compensate for misalignment of various components, and they provide some range of motion. The most usual components they attach to are linkages, rods and shafts, but they really attach to an even wider array of cylindrical parts. Spherical rod end bearings vaguely resemble the ends of ratchet wrenches. At the end of a slender shaft is a round housing that holds a bearing.

Material choices for rod end bearings include both ferrous metals as well as brass and bronze. They often have a coating, such as zinc. There are also plastic spherical rod end bearings. To select an appropriate rod end bearing, you'll need to understand the basic specifications, some of which you'll see described below:

1. The inside diameter of the hole through the spherical rod end bearing is the bore diameter.

2. The diameter to the top of the threads is the major diameter.

3. The distance through the bore is the bearing thickness.

4. The outside diameter of the entire housing is the housing diameter.

5. The distance from the bottom of the shank to the top of the housing is the overall length.

Action Steps
The best contacts and resources to help you get it done

Buy from a quality spherical rod end bearings supplier

There are many good spherical rod end bearings distributors. When buying, make sure to match the load capacity and max misalignment with your application parameters. Overshooting a little is not a bad idea.

I recommend: Igus sells Igubal bearings. They are vibration, dust and liquid resistant; and if the company doesn't have what you want, it will custom tool parts to fit your specs. Igus has no minimum order requirement. For custom rod end bearings, head to Alinabal Motion Transfer Devices.

Choose the right thread type from those produced by spherical rod end bearings manufacturers

The shafts of spherical rod ends are typically of two types. Female with threads on the inside, or male with threads on the outside. Also, though most rod end bearings have the usual 'righty-tighty' threading, some tighten counterclockwise to fit special situations. Of course, there are standard English thread sizes in addition to metric sizes.

I recommend: As is common with a spherical rod end bearings manufacturer or supplier, Grainger organizes their rod end bearing stock by male and female (shank). Also take a look at Aetna Screw Products' website. They have quick-read charts that include thread size, as well as detailed dimensions for whole rod ends.

Find spherical rod end bearings in metric sizes from spherical rod end bearings suppliers

Some suppliers of spherical rod end bearings have better selections of the metric spherical rod end bearing. If this is what you need, don't settle for skimpy selections.

I recommend: The Aurora Bearing Company carries metric rod end bearings in various grades, from lighter-weight, economical parts to heavy duty rod end bearings. Maryland Metrics is another metric source, with many more metric parts than English (or fractional, i.e. 1/4, 3/5, etc.).

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Keep in mind that the max angular misalignment a bearing allows is only about half the bearing's total range of movement.