Bearings: Ball vs. Roller

A bearing is a mechanical device used to prevent direct metal to metal contact between two elements in relative motion. This prevents friction and heat generation and ultimately slows the natural process of wear and tear. Furthermore, because bearings replace sliding motion with low friction rolling, energy consumption is also reduced. In addition to this, bearings also serve the purpose of transmitting loads from the rotating element to the housing. This load can be radial, axial, or a combination of both. Though a wide range of bearing types exist, they are generally separated into one or two major types: ball bearings and roller bearings. This blog will discuss both of these bearing types and their unique characteristics.

Ball bearings are the most common type of bearing used. These consist of a row of balls that operate as rolling elements. The balls are concealed between two ring-shaped metal pieces known as races. The inner race is free to rotate while the outer race remains fixed. Ball bearings are commonly used to control vibration and rotational motion. For instance, ball bearings connect the shaft to the motor housing in electrical motors, where the shaft is free to rotate but the housing must remain stationary. The advantages of ball bearings include good wear resistance, lack of need for much lubrication, low friction, long service life, easy to replace, small dimensions, affordability, and ability to handle thrust loads.

The most common types of ball bearings include deep groove ball bearings, angular contact bearings, self-aligning ball bearings, and thrust ball bearings. There are three scenarios in which ball bearings are ideal. First, because their design makes them ideal for handling axial loads, they should be used when thrust loads are present. Second, ball bearings should be used for light loads. Due to their ball-shaped rolling elements, force is concentrated on very few points of contact, making them susceptible to failure under heavy loads. Finally, ball bearings are ideal for use at high speeds. The small points of contact also mean there is less friction and therefore can operate at higher rotational speeds.

Instead of balls, roller bearings contain cylindrical rolling elements as the load-carrying elements between the races. While similar to balls, an element is considered a roller if its length is greater than its diameter, no matter how slightly. Because they are in line contact with the inner and outer races, roller bearings can support greater loads. Like ball bearings, there are many different types of roller bearings. This includes cylindrical roller bearings, spherical roller bearings, tapered roller bearings, and needle roller bearings. Before selecting the appropriate bearing type, consider the type and amount of loading, service conditions, and the possibility of misalignment.

The main advantages of roller bearings are their easy maintenance, low friction, ability to withstand high radial loads (some types of roller bearings can also take high axial loads), high accuracy, ability to adjust axial displacement, and low vibrations. Roll bearings are ideal for use in applications with heavy loads. Because they provide a larger area of contact, the load is distributed more evenly. Their contact area also makes them ideal for use at lower speed. At higher speeds, the larger contact area creates more friction resulting in greater heat generation and faster wear and tear.

For bearings of all types and much more, look no further than ASAP Fasteners, a trusted supplier of parts for a wide range of industries. Owned and operated by ASAP Semiconductor, we are an online distributor of aircraft parts as well as parts pertaining to the aerospace, civil aviation, defense, electronics, and IT hardware markets. We’re always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, call us at 1-714-705-4780 or email us at


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