How to Identify Bearings by Number? Bearing Numbering System

Bearings provide major importance in various mechanicals. They are available in different sizes and measures. Bearings contain numbers as well. The numbers help in the process of identification. Bearing numbers are also termed pattern numbers. As a top bearing supplier in India, we feel the need to educate non-technical persons having requirements of bearings. Today, we will discuss the bearings and how to identify bearings by numbers?

How to Identify Bearings by its number of tapered, roller, and ball bearing?

Bearing numbers is essential in choosing the required bearing type. It contains the supplementary codes and basic numbers. The bearing number code can also be termed as the sub-divisions of bearing. The sub-division demonstrates the types of bearing with numbers, series, bore type, and sealing.

Every bearing is composed of different codes and numbers. In the case of tapered bearing, the code is 32/ T. roller bearings and ball bearings are of several categories. Each category carries different codes as well as numbers. To know the codes of the bearing types, follow the given bearing specification chart below:

(Table 1: Types of codes and bearings)

How to calculate bearing size?

The calculation of bearing size is easy to understand. For example, the bearing no. is 6203RS. Here, 6 signify the bearing type whereas 2, 03, and RS signify the bearing series, bore type, and sealing. The calculation of the bearing size undergoes several procedures:

Bearing calculation is the easy identification of the type of bearing. Mainly, in the case of supplementary codes. Consequently, the calculation is different for inch bearing.

In the case of Inch Bearing, the first digit must be ‘R’. ‘R’ also indicates the size of the bearing. That must be 1/6th of an inch. For example, R4-3RS is the bearing number. Here, R4 indicates the inch bearing. R4 also denotes the bore size of the bearing. Mainly, R4 is equal to 4/16 or 1/4th of an inch.

Secondly, the bore size of the bearing. Bearing size is calculated by the relevant dimension. It is measured in millimetres. The third and fourth digit of the bearing number describes the bore size. The bore size varies from 0 to 3 which indicate 10 to 17 in mm. In this case, if there is no fourth digit in the bearing number, the third digit will denote the bore number. For example, the bearing size is 234. So, that actively demonstrates that 4(=4mm) is the bore size.

In another case, the bearing number is 6305ZZ. That actively demonstrates that the third and the fourth digit is the bore size. Equally, 05 is the bore size. Therefore, 05 are equal to 25 mm of the bearing bore size.

(Table 2: Bore size and the digit)

Measurements of bearings

There are 3 ways for the measurement of bearings. That is the Inside Diameter (ID), Outside Diameter (OD), and width (W).

The procedure follows an equation or an order, that is, Bearing measurement = ID x OD x W

Clearance is the total distance between the inner rings to the outer ring. Such as, when one among the rings is rotating and the other is fixed. Bearing clearance is of 5 types normal clearance, standard clearance, C2, C3, and C4.

Among them, normal clearance and C3 are the main clearance. The normal clearance shows no suffix. Standard clearance has no suffix as well as the prefix. C3 delivers faster running speed and higher temperature with no failure. C2 is less than standard clearance. At last, C4 shows an outcome faster than C3.

How to find a bearing number?

In the case of understanding the bearing size, it is necessary to learn the components precisely. Such as each bearing carries different codes which determine the type. The medium toughness of the bearing is observed by the bearing series. The bore no. describes the inner diameter of the bearing. The diameter is measured in millimetres.

In the end, sealing indicates the type of shielding done in bearing. ZZ or 2Z is the type of metal bearing. And, 2RS, 2RS1, 2RSR are the types of rubber bearings. This demonstrates the entire bearing number nomenclature.

(Table 3: Series Code with description)

(Table 4: The types of shielding with description)

Let’s know the procedures for the identification of the bearings. 6203ZZC2 is the bearing number. From ‘62’,’ 6’ describe the type of bearings. By following table 1, it indicates that it is a single-row deep groove ball bearing. ‘02’ indicates the bearing series. By following Table 4, it indicates that it has light toughness. Here, 03 describes the bore number.

Following table 2, 03 is equal to 17mm bore size. ZZ is the type of metal shielding. That indicated that the bearing is shielded on both sides. In the end, C2 describes the clearance code that is less than standard.

It is easy to understand the bearing numbers. Bearing numbers shows the difference in shape, size, toughness, etc. It will help you in choosing and determining the required bearing precisely. Before that, it is essential to remember the codes as well as numbers. Follow the bearing number and size chart and identify your bearings.