Bearing Number and Its Significance

Bearing Number and Its Significance

A bearing number is a unique alphanumeric code that provides specific information about a bearing, such as its type, dimensions, design features, and material specifications. Generally, bearing numbers are divided into several parts, each indicating different characteristics of the bearing:

1. Bearing Type: The first digit or letter denotes the bearing type (e.g., deep groove ball bearing, tapered roller bearing).
2. Series or Load Capacity: The second digit indicates the bearing series, representing its load-bearing capacity (e.g., extra light, light, medium, heavy).
3. Bore Size: The following digits specify the inner diameter or bore size of the bearing, typically calculated using a specific formula.
4. Sealing or Shielding Type: Letters and numbers after the bore size indicate the type of sealing or shielding (e.g., metal seal, rubber seal).
5. Clearance Specification: Additional letters indicate the internal clearance of the bearing (e.g., normal clearance, C3 for higher clearance).

Why is Bearing Number Important?

1. Identification: Bearing numbers help accurately identify the type and specifications of a bearing, essential for replacement and maintenance.
2. Compatibility: Knowing the bearing number ensures it is compatible with specific machinery, assisting engineers in selecting the right bearing for their applications.
3. Performance: Bearing numbers provide insights into performance characteristics, such as load capacity and speed rating, which are crucial for ensuring the efficiency and reliability of mechanical systems.
4. Standardization: Bearing numbers follow international standards (e.g., ISO, ANSI), simplifying communication and understanding among engineers, suppliers, and manufacturers.
5. Inventory and Documentation: In manufacturing and repair environments, bearing numbers assist in inventory management and tracking, making it easier to order, stock, and manage components.

Bearing Number Breakdown by Type (First Digit)

• (1): Self-Aligning Ball Bearing
• (2): Barrel and Spherical Roller Bearing
• (3): Tapered Roller Bearing
• (4): Deep Groove Row Ball Bearing
• (5): Axial Deep Groove Ball Bearing
• (6): Deep Groove Ball Bearing
• (7): Single Row Angular Contact Bearing
• (8): Axial Cylindrical Roller Bearing

Bearing Series by Load Capacity (Second Digit)

• 0, 1: Extra Light
• 2: Light
• 3: Medium
• 4: Heavy
• 5: Extra Heavy

Bore Size (Third and Fourth Digits)

• 00: 10 mm bore
• 01: 12 mm bore
• 02: 15 mm bore
• 03: 17 mm bore

For other numbers, multiply by 5 to determine the bore size (e.g., 06 means 30 mm bore).

Sealing and Shielding Types:

• 2RS: Rubber seal on both sides
• RS: Rubber seal on one side
• 2Z/ZZ: Metal seal on both sides
• Z: Metal seal on one side
• E: Reinforced bearing
• K: Tapered bore

Clearance Types (C3 Specification):

• CN: Normal clearance
• C1: Less than normal clearance
• C2: Less than C1 clearance
• C3: Greater than normal clearance

Additional Information from ASTM and ASME Standards

Following ASTM D3336 (Standard Test Method for Life of Lubricating Greases in Ball Bearings at Elevated Temperatures) and ASME B15.1 (Safety Standard for Mechanical Power Transmission Apparatus), bearing numbers and their specifications ensure safety, reliability, and compliance with operational limits. These standards guide the selection of materials and design features that directly impact bearing performance, including load capacity, tolerance to heat, and suitability for various industrial environments.

Conclusion

The bearing number offers critical information for identifying and selecting the right bearing for industrial and mechanical applications. The unique number system helps standardize bearings globally, ensuring compatibility, performance, and safety in various engineering fields.