When you shop for bearings, you may have noticed that model numbers often include letters or combinations of letters after the main code. These suffixes are essential for identifying specific features such as seal types, cage materials, internal clearances, and more. Here’s a breakdown of the most common ball bearing suffixes and their meanings:
Common Ball Bearing Suffixes for Seals and Shields:
- ZZ – Double-Shielded (Metal Shields)
- The bearing has two non-contact metal shields (one on each side) that prevent larger contaminants from entering while allowing some level of lubricant flow.
- 2RS or RS – Double-Sided Rubber Seal (Contact Seals)
- Bearings with this suffix have rubber seals on both sides (2RS) or one side (RS) that provide tight protection against dust and moisture, fully sealing the bearing and keeping the lubricant inside.
- Z – Single-Shielded (Metal Shield on One Side)
- The bearing has a metal shield on only one side, offering basic protection from contaminants while leaving the other side open for lubrication.
- RZ – Low-Friction Seals
- These bearings feature non-contact rubber seals designed to reduce friction and maintain a balance between protection and low drag.
- VV – Non-Contact Rubber Seals (Low-Friction)
- Non-contact rubber seals on both sides, providing better protection than ZZ bearings but with lower friction compared to RS/2RS types.
- N – Snap Ring Groove
- The bearing is equipped with a groove to accept a snap ring, which can simplify mounting and axial positioning.
- NR – Snap Ring with Groove
- Same as "N" but includes the snap ring installed in the groove, further simplifying installation and securing axial loads.
Other Suffixes for Ball Bearing Features:
- C3 – Increased Internal Clearance
- Bearings with this suffix have greater clearance between the rolling elements and raceway, allowing for higher speeds or compensation for thermal expansion in applications with high temperatures.
- C4 – Even Larger Internal Clearance
- Greater clearance than C3, often used in even higher temperature or speed applications.
- E – Enhanced Capacity
- The bearing is designed with a reinforced cage or extra capacity, making it suitable for heavier loads.
- K – Tapered Bore
- The inner bore of the bearing is tapered rather than cylindrical, allowing for easier installation in certain applications.
- M – Machined Brass Cage
- Indicates that the bearing uses a brass cage for greater strength and durability in demanding environments.
- P5 or P6 – Precision Grade
- Bearings marked with these codes have enhanced precision, with P5 being more precise than P6, often used in applications requiring extremely accurate performance.
- U – Outer Ring Modified
- The outer ring of the bearing is modified for specific mounting or performance requirements.
- TN – Polyamide Cage
- A lightweight, low-friction plastic (polyamide) cage that helps reduce wear and heat generation in high-speed applications.
- W – Water-Resistant Bearing
- Indicates that the bearing is designed for environments where water exposure is a factor, often with additional seals or coatings.
- X – Special Design
- Often used as a manufacturer-specific designation for custom or enhanced features not covered by standard suffixes.
Conclusion: How to Choose the Right Bearing
Understanding these suffixes allows you to choose the right ball bearing for your specific application, ensuring you get the best performance and durability. Whether you're dealing with high speeds, dusty environments, or heavy loads, there’s a bearing configuration to match your needs.
