What Are the Races in Ball Bearings?

Ball bearing by Monroe Engineering

When researching the different parts of ball bearings, you may come across races. Ball bearings don’t just contain smooth and round balls. They contain other parts, including races. Whether they feature glass or stainless steel balls, most ball bearings feature races. To learn more about the races in ball bearings and how they work, keep reading.

Overview of Ball Bearing Races

Races are essentially tracks that allow the balls within ball bearings to glide while generating little or no friction. They offer a fixed path on which the balls can roll. Ball bearings require races to control their respective balls. With races, the balls can roll along a fixed path.

If you take apart a ball bearing to inspect its races, you’ll notice that they have a horizontal groove in the center. This groove serves as the track for the bearing’s balls. Each race is designed with a groove in an appropriate size for the balls with which it’s used.

Inner vs Outer Races

Ball bearings have an inner race and an outer race. As the name suggests, outer races are those found on the outside of the balls, whereas inner races are those found on the inside of the balls. The balls within a given ball bearing are sandwiched between these two types of races. All ball bearings have an inner race inside of the balls and an outer race on the outside of the balls.

Inner and outer races provide containment for the bearing’s balls. If a bearing only has an inner or an outer race, the balls won’t be contained. The inner and outer races form a container for the balls. At the same time, they provide the balls with a set of tracks on which they can roll.

Other Parts of Ball Bearings

Ball bearings contain other parts besides an inner and outer race. All ball bearings, of course, have balls. Some of them have glass balls, whereas others have stainless steel balls. You can even bearings with acetal, ceramic and polypropylene balls, each of which offer their own benefits.

Another part of ball bearings is the cage. The case is the middle part between the inner and outer races. It’s essentially a housing unit for the balls. With that said, not all ball bearings have a cage. Rather, cages are typically found in Conrad ball bearings. Other types of ball bearings may only contain balls and an inner and outer race.