Detailed Explanation of Bearing Suffix Codes
In bearing models, the basic code mainly represents the bearing type and size, while the suffix code is used to indicate special requirements of the bearing, such as internal structure, tolerance grade, clearance, cage material, etc. For bearing selection, procurement, and sales, understanding these codes is very important.
Today, we will briefly explain a few of the most common bearing suffix codes.
1. Internal Structure Codes
Internal structure codes are used to represent different internal design structures of the same type of bearing, usually indicated by letters following the basic model number.
For example, in angular contact ball bearings, different contact angles are represented by different codes: C: contact angle 15°; AC: contact angle 25°; B: contact angle 40°. Different contact angles result in different axial load capacities, making selection critical in high-speed or heavy-load conditions.
2. Tolerance Grade Codes
The tolerance grade of a bearing primarily reflects the manufacturing and operational accuracy of the bearing; the higher the grade, the higher the precision.
Common tolerance grades include:
Tolerance Grade | Code
----------------|-----
Grade 2 | P2
Grade 4 | P4
Grade 5 | P5
Grade 6 | P6
Grade 6X | P6X
Grade 0 (Standard)| P0
P0 grade is the standard grade bearing and is generally not marked in the model. High-precision bearings such as P4 and P5 are often used in machine tool spindles and precision equipment.
3. Radial Clearance Codes
Before installation, there is a certain gap between the inner and outer rings of a bearing; this is the radial clearance. Different working conditions require different clearance grades.
Common clearance groups are:
Clearance Group | Code
Small clearance | C1
Smaller clearance | C2
Standard clearance | C0
Larger clearance | C3
Large clearance | C4
Extra large clearance | C5
C0 is the standard clearance and usually is not marked in the bearing model. C3 clearance is widely used in motors and high-speed equipment.
Bearing suffix codes mainly indicate three things: 1. Internal structure (e.g., contact angle) 2. Manufacturing precision (tolerance grade) 3. Operating clearance (clearance size)
Understanding these codes allows you to roughly determine the performance and application scenario of a bearing. Being familiar with this basic knowledge also enables more professional and efficient selection for customers.
Post time: May-20-2026
