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What is bearing number and how to identify it?

wallpapers Tech 2020-06-24
A bearing number is series of numbers composed of a basic number and a supplementary code, denoting bearing specifications including bearing type, boundary dimensions, running accuracy, and internal clearance.
Usually the bearing number are composed by a group of numbers with letters. Therefore, with a bearing number, you not only find the specific type of bearing but also it’s series and bore size number.
 
For instance, let’s take an example of a specific bearing number 6203RS. In the given bearing number:
 
The first number i.e. “6” represents the “type of bearing”.
The second number i.e. “2” represents the “ bearing series”.
The third and fourth number i.e. “03” represents “bore size”.
And the last two letters i.e. “RS” represents the “Sealing/ Seal”.
 

How to identify bearing number?
In this section, we will discuss how to identify bearings by number? The bearing number basically has 4 parts. these are:
 
Bearing type based on bearing number
Generally, when discussing various types of bearing numbers, there are basically four basic bearings. these are
 
Radial ball bearings
Radial roller bearings
Thrust ball bearing
Thrust roller bearings
Radial ball bearing number
In this type of bearing, the friction load is only borne by the radial bearing. In addition, they run through lubricating steel balls placed between grooved rings.
 
When talking about its other names, they tend to call them deep groove bearings or Conrad bearings. For example, they are accommodated in various automobile industries and industrial machinery.
 
However, the common radial ball bearings are numbered 1, 2, 3, 5, 6, and 7.
 
Radial roller bearing number
As the name suggests, they have a rolling element that cleverly places the load between the two races. Therefore, they tend to have relative motion of these races, and these races eventually act with little resistance to rolling. This also hinders the sliding of radial roller bearings.
 
The common uses of radial roller bearings are:
 
Light loads, such as bicycle ball bearings
Heavy loads, such as cars and trucks, tapered roller bearings.
The most common bearing numbers for radial roller bearings are N, NU, NN, 2 and 3.
 
Thrust ball bearing number
When it comes to thrust ball bearings, they have rotating parts that only bear axial loads. However, they are not for heavy-duty machinery. This is why their size is very small, about 2mm to 340mm.
 
In thrust ball bearings, they have two races, both of which are equipped with lubricated bearing balls to withstand axial loads. In this type, the fixed part is connected to one seat ring, while the other seat ring controls the movement of the axial load.
 
The most common thrust ball bearing number is "5". In addition, you can also view our special columns for thrust bearings from here.
 
Thrust roller bearing number
When it comes to thrust roller bearings, they have single-row, double-row and triple-row races, they can only withstand axial loads, but only loads. Cylindrical thrust roller bearings and tapered roller thrust bearings are some common and most commonly used thrust roller bearings.
 
These types of bearings have relatively low resistance even under load. This is due to its good weight distribution system. Generally, the most common bearing size for thrust roller bearing numbers is "2".
 
Type code for bearings:
 
The first table on the topic of how to identify bearings by number: Types of bearing and their code.
S.No. Bearing Name Type Code
1 Self Aligning Ball Bearing 1
2 Spherical Roller Bearing 2
3 Double Row Angular Contact Ball Bearing 3
4 Double Row Ball Bearing 4
5 Thrust Ball Bearing 5
6 Single Row Deep Groove Ball Bearing 6
7 Singular Row Angular Contact Bearing 7
8 Felt Seat Bearing 8
9 Tapered Roller Bearing 32/T
10 Inch Bearing R
11 Cylindrical Roller Bearing N
12 Needle Roller Bearing NA
13 Double Row Roller Bearing NN
14 Needle Roller Bearing With Closed Ends BK
15 Needle Roller Bearing With Open Ends HK
16 Needle Roller and Cage Thrust Assembly K
17 CARB Toroidal Roller Bearings C
18 Four Point Contact Bearings QJ
 
Bearing Series and Their Code in Bearing Number
To demonstrate the strength and toughness of a bearing, bearing series is very useful. The toughness of a bearing can be categorized into seven broad categories. These are:
Very thin section
Extra thin section
Heavy 
Medium
Light
Extra Light Thrust
Extra Light
In general, the bearing series code demonstrates by the second digit in the actual bearing number. Hence, the second digit dignified the bearing series.
Table for Bearing Series and Their Code
The second table on the topic of how to identify bearings by number?: Bearing Series and their Code.
S.No. Bearing Series Series Code
1 Extra Light 0
2 Extra Light Thrust 1
3 Light 2
4 Medium 3
5 Heavy 4
6 Extra thin section 8
7 Very thin section 9
Bore Size of Bearing
A bore size or bore diameter is called to be the distance between the inner race (deep grooved wall). They are broadly categorized as fit and tight fit. 
While talking about how to find and calculate the bore size of the bearing, it is calculated by the finding of its relevant dimension. The inner race diameter should be measured in millimeters.
With the value of bore diameter, one can ensure the circular fit of bearing for the desired equipment. Therefore, if you require a bearing for the equipment you have to first find the inner diameter of the bore. 
In a bearing number, the 3rd and 4th numbers represent the bore size of the bearing. The general bore diameter for a bearing ranges from “00” to “05”
But one point that one should consider is that in case of no four-digit, let’s say ‘624” then the 3rd digit represents the bore size of bearing. 
Table of Bore Size and Corresponding Bearing Code
The third table on the topic of how to identify bearings by number? Bore size/ bore diameter along with their corresponding bearing code.
S.No. Bore Size/ Diameter Bearing Code
1 10 00
2 12 01
3 15 02
4 17 03
5 20 04
6 25 05
7 30 06
8 After this, Bore size= Code x 5 07
Shielding or Sealing of Bearing in Bearing Number
In any type of bearing the lubrication is done to reduce the resistivity and also to decrease the wear of the bearing components.
To make lubrication full proof, shielding or sealing is done. That’s why they not only lubricate the bearing but also prevent it from contamination. 
Lubrication can be sealed (contact) or a shield (non-contact). But when the bearing has to operate in a vacuum, then no-seal is used. In those cases, the bearing will be externally lubricated.
In a bearing number, a shield/seal/no-seal/ is represented by the two-block alphabets. The following table represents all the common types of shielding or sealing in bearing numbers. 
Table of Shielding or Sealing of Bearing in Bearing Number
The fourth table on the topic of how to identify bearings by number? Shielding or Sealing of Bearing in Bearing Number.
S. No. Shield/ Seal/Others Bearing Code
1 Brass Cage M
2 One Side Shielded Z
3 Both Sides Shielded ZZ
4 One Side Sealed RS
5 Both Side Sealed 2RS
6 One Side Non-Contact Seal V
7 Both Sides Non-Contact Seal VV
8 Both Sides Contact Seal DDU
9 Snap Ring and Groove NR
 
From the above content, you may have a basic knowledge on bearing numbers. But usually, you need not to be a professional technician to find your needed bearing type. Just find the old one, and see the bearing code, try to find the same one in the store or from the suppliers website. If you still can’t find your wanted bearings, just contact our sales team and our sales engineer will provide you a professional solution.
 
Eric bearing Limited has established cooperative partnership with some distributors authorized the world renowned manufacturers like Sweden SKF BearingFAG Bearings and INA Bearing, Japan NSK Bearing, Japan NTN  Bearing, Japan IKO Bearing,Japan KOYO Bearing,Japan NACHI Bearing and America  TIMEKN Bearing ,etc. If you are bothering about how to select a suitable ball bearing, please feel free to contact and get a quote.

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