Bearing Nomenclature

Bearing number have different meanings. But how do you identify the first, second, third, and fourth bearing number meaning from different manufacturers? Read on! This article explains in detail about bearing numbers. 

What Does Bearing Number Mean?

A bearing number comprises supplementary code and a basic number that signifies the specifications of the bearing as well as the type of bearing, internal clearance, boundary dimension, and running accuracy. In addition, bearing numbers play a crucial role in bearing classification. They give you insight into the typical usage, suitability, and durability of specific applications. In conclusion, if you understand the standard bearing number meaning, you’ll be able to identify the bearing you need correctly irrespective of the brand.

Importance Of Bearing Number Meaning

Bearings are important parts utilized in diverse machinery and equipment that necessitate movements between two moving parts to reduce friction. Furthermore, bearing numbers give you an insight into the type, design, size, as well as other key specifications of the bearings. Below are some important and common aspects of bearing numbers:

• Type And Designation: For example ball bearing, thrust bearing, roller bearing, etc bearing number consists of the bearing type. Sometimes, it indicates the bearing designs, such as tapered roller bearings, spherical roller bearings, and deep groove ball bearings.
• Size And Dimensions: Sometimes bearing number shows the size and dimension of the bearing, the bore diameter, width, outer diameter, and other relevant measurements. This information is vital for you to choose the right bearing for your application.
• Load Capacity And Speed Ratings: Bearing numbers also give information about the load capacity, speed ratings, and other performance features of the bearing. This will show you if the bearing is a good fit for a particular application based on the operating conditions you are expecting.
• Manufacturing Details: Sometimes the bearing number gives you information about the country of origin, manufacturer, and other manufacturing details. This is good for traceable purposes and quality control.
• Interchangeability: International organization for standardization (ISO) is one of the organizations that standardize bearing numbers to make sure bearing numbers from various manufacturers are interchangeable. This will allow you as a user to suspend compatibility issues when replacing your bearings.

How To Read And Identify Bearing Number

Basic Structures Of Bearing Numbers

Bearing numbers are made up of three different parts which are the prefix, basic designation, and suffix. For example the NTN radial ball bearing code TS2-6206 x1 LLB N c3 p5/2AS’

‘TS2’ represents the prefix, meaning “Heat stabilized up to 320°F (160°C)”;

‘6206’ is the basic designation – Digit identification of bearing;

‘X1’, ‘LLB’, ‘C3’, ‘P5′, 2AS’ are the suffixes.

Bearing Number Components(Prefix)

Prefixes primarily show a particular part of a bearing and can also detect various bearing variants. Take a look at the NTN prefix for example.

In terms of thermal stability:

   In terms of materials:

     SKF deep groove ball bearing prefix code are:

First Identification Of Bearing

Bearings’ first digit carries substantial significance as it often helps to identify the type of a bearing. It’s useful when it comes to identifying the core design of the bearing. For example, in ‘6206’, the first digit “6” refers to single row deep groove ball bearing’.

The table below shows diverse bearings with their code type.

 Second Identification Of Bearing

In bearing numbers, the bearing series is usually indicated by the second digit. Certain numbers indicate light, medium, or heavy series depending on how sturdy the bearing is. As a result, this number offers important information about how well the bearing can manage various load scenarios.

For example, “very thin section” is indicated by the second digit “2” in the number ‘6206’

The table below shows different bearing series with their corresponding numeric codes.

Bearing numbers’ third and fourth digits are very important since they usually indicate the bearing’s inner diameter (ID) in millimeters. They give essential information about the bearing’s compatibility with the shaft it’ll be mounted upon.

The table below says it all.

Bearing number bore size ranges from o to 3, indicating 10 to 17 mm.

For numbers above ’03’, you can calculate the bore size 5 times the value represented by the 3rd and 4th digits in the bearing number.

For instance, in “6206”, ’06’ corresponds to the bore size, and thus, “06” translates to a bearing bore size of 6*5=30 mm.

When the bearing number lacks the fourth digit, the bore size is represented by the third digit. For example, the digit ‘4’, or 4mm, indicates the bore size for a bearing size of ‘234’

Bearing Number Components (Suffix)

Bearing suffixes show different designs or variants that are different from the main or current basic design. For example, sealed and shielded bearings comprise different suffixes.

For “6206 LLB”, “LLB” represents a non-contact rubber seal bearing.

The table below shows some common seal or shielded bearing suffixes.

 Different bearing brands have their various expanded suffixes.

The table below refers to NTN expanded suffixes.       

 See the below table is for SKF   

There are other suffixes apart from seal and shield. They include heat treatment, cage design, clearance, material, accuracy, preload, quiet running, lubrication, stabilization, and other special specifications.

Bearing Suffix For Outer Surface Dimension

Bearing Suffix For Sealings And Closures

Seal or shield-bearing suffix designations are different depending on the manufacturer. Nevertheless, the following are some examples of common suffixes:

• ZZ: Double metal shields.
• 2RS: Double rubber seals, typically non-contact seals.
• DU: Double contact seals, full contact seals.

Bearing Suffixes For Cage Materials

Bearing Suffixes For Precision Tolerance

ISO 199 universal standard, defines the tolerance classes and any tolerance characteristics values for thrust bearing types. For radial bearings, ISO 492 is equivalent. 2014 saw the alignment of these standards with the overall ISO geometrical product specification (GPS) standards; ISO 5459 and 1101 are two examples of these standards.

Bearing Suffixes For Bearing Clearances

The suffixes for bearings with unique precision tolerances and clearances are combined to create the bearing numbers. For example, a bearing with C3 clearance and P6 tolerance would be designated as P63. Suffixes commonly used to signify internal clearance include the following:

• C0: Normal clearance
• C2: Smaller clearance
• C3: Greater clearance
• C4: Larger clearance

Bearing Suffixes For Dimensionally Stabilized Bearings

Tips For Decoding The Meaning Of Bearing Number

1. 1. Leverage Resources: Refer to manufacturer guides and online tools for bearing identification.
   2. Understand Structure: Understand the basic designation, suffixes, and the importance of prefixes.
   3. Avoid Assumptions: Make sure that you verify the bearing number of different manufacturers assuming they are identical.
   4. Check Errors: Pay attention to typos, they are capable of altering bearing specifications.
   5. Ask When Uncertain: Seek expert opinion when unsure about a bearing number.

Bearing Series Code

 Configuration Of Bearing Number

Conclusion

In conclusion, bearing nomenclature plays a crucial role in identifying types of bearings irrespective of the manufacturer. Having an in-depth knowledge of the bearing numbering will help you switch bearings from different manufacturers without difficulty.