In the world of bearings, the ABEC (Annular Bearing Engineering Committee) rating plays a crucial role. But what exactly does this rating mean, and how relevant is it for different applications? In this blog post, we delve deeply into the ABEC rating system and explain why it is largely irrelevant for certain purposes like skateboarding. Whether you're an engineer, a DIYer, or a mechanic, here you'll find all the important information presented in an easy-to-understand way.
What is the ABEC Rating?
The ABEC rating is a standardized system for measuring the dimensional tolerances of bearings. It was introduced over 50 years ago by the Annular Bearing Engineering Committee (ABEC), a subset of the American Bearing Manufacturers Association (ABMA). The task of this committee is to establish acceptable tolerances regarding the dimensional and running accuracy of all bearings.
ABEC ratings range from 1 (lowest level) to 9 (highest level) and indicate how tight the tolerances of a bearing are. The higher the rating, the tighter the tolerances, and the more precise, efficient, and faster the bearing can theoretically run. However, it's important to understand that the ABEC rating reflects only a part of a bearing's performance characteristics.
The ABEC scale and corresponding ISO 492 ratings are as follows:
ABEC 1: ISO Class 6X
ABEC 3: ISO Class 6
ABEC 5: ISO Class 5
ABEC 7: ISO Class 4
ABEC 9: ISO Class 2
For example, on an ABEC 1 bearing with an outside diameter of less than 2 inches (approx. 5 cm), the width of the outer ring can deviate by up to 0.0050 inches (approx. 0.127 mm). However, for an ABEC 7 bearing with the same diameter, the deviation of the outer ring width must not exceed 0.001 inches (approx. 0.025 mm).
ABEC tests two main factors to determine tolerance levels: dimensional accuracy and running accuracy. Dimensional accuracy includes physical bearing characteristics such as bore diameter, outer diameter, bearing width, allowable inner ring taper deviation, and shape error. Running accuracy, on the other hand, measures inaccuracies such as axial runout or inner and outer ring runout.
Why is the ABEC Rating Irrelevant for Skateboards?
Although the ABEC rating can be helpful in selecting bearings, it is largely irrelevant for skateboard applications. The reason for this is that the bearings quickly become irregular during skating, causing the ABEC rating to lose its significance.
Factors such as shielding, materials, and lubrication have a much greater impact on the performance of skateboard bearings than the ABEC rating. In fact, an ABEC 1 bearing is more than precise enough for most skateboard, longboard, and cruiser applications. Spending more money on bearings with higher ABEC ratings like 7 or 9 is unnecessary and does not provide any significant performance benefits.
How to Choose the Right ABEC Rating?
Choosing the right ABEC rating for your bearing application requires a good understanding of what the ABEC scale represents. Most available bearings belong to ABEC grades 1 and 3 and function very well. These bearings are in the middle of the spectrum and are often used in non-precision applications such as automotive components, skateboards, electric motors, and gearboxes.
Stricter tolerances are typically required in applications where bearings must operate at very high RPMs or where precise positioning is essential. For products like high-speed routers, where speeds exceeding 30,000 RPM are reached, bearings with ABEC ratings of 7 or 9 are required. Manufacturing these higher-grade bearings requires more precise machining and longer production times, resulting in significantly higher prices – often up to five times higher than lower-rated bearings.
Other applications that use bearings in the upper range of the ABEC scale include:
Machine tools
Aerospace components
Robotics
Medical devices and equipment
Devices that must maintain high RPMs
It's important to note that while the ABEC rating can help determine bearing performance, many other factors must be considered when selecting a suitable bearing. For example, the ABEC rating does not account for material properties, impact resistance, side loading, lubrication, clearance, noise generation, and installation requirements.
For these reasons, it is entirely possible for two bearings with a similar ABEC rating to exhibit significantly different performance in different environments. In some situations, bearings with lower ABEC ratings may even outperform higher-rated bearings in certain applications.
At Euro Bearing Deutschland, we have decades of experience in distributing all types of bearings for buyers in Germany and internationally. Our extensive inventory offers solutions for almost any application. We are specialists in application-specific bearings and ensure that our products meet the requirements of our customers.
