Views: 0 Author: Site Editor Publish Time: 2024-10-18 Origin: Site
As we all know, bearings are divided into many types. Different design and specification bearings will work in different application environments. Therefore, how to identify the right one quickly and select correctly is very important for the engineers, technicians, and users. Thus, the industry formed standardized bearing code systems for the purpose of facilitating communication among enterprises and users.
The significance of bearing codes will be elaborated detailedly in this article. By deciphering these codes, one can make optimum choices of bearings for various purposes, which enhances both the efficiency and reliability of mechanical design. It will not only be helpful in maintenance and repair work daily, but it will also provide support to design innovation.
It should be noticed that the naming of bearing models is not unified all over the world. The standard of bearing and naming method may be different for different brands and production plants. A user needs to confirm carefully when purchasing a bearing.
The bearing number is an engineering language, usually composed of letters and numbes. Bearing number is used to describe bearing type, structural dimensions, tolerance grade, clearance grade, material properties, etc., and plays an important role in bearing classification.
Bearing number consists of basic code and supplementary code.
The basic code includes bearing type, bearing structure, size series and inner diameter size. The basic code of each standard bearing is usually composed of three to six digits, or a combination of letters and numbers. The digits are generally arranged from left to right. The first digit (or letter) arranged from left to right indicates the type of bearing.
Supplementary codes include deformation of the ring, change of material, change of cage, seal and dustproof device, pairing combination, clearance group, tolerance grade, special performance requirements, etc. The supplementary code is expressed on the left and right of the basic code in the form of prefix code and suffix code.
For example:
| Bearing Codes Sequence | |||
| Prefix Code |
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| Basic Code | Common Rolling bearings |
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| Width (height) series code | ||
| Diameter series code | |||
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| Needle Roller Bearings |
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| Suffix Code |
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The basic bearing code is mainly composed of type code, size series code and inner diameter code.
Here are the detailed information:
| Bearing Type Code | Bearing Type Name |
| 0 | Double row angular contact ball bearing |
| 1 | Self-aligning ball bearing |
| 2 | Spherical roller bearing and thrust spherical roller bearing |
| 3 | Tapered roller bearing |
| 4 | Double row deep groove ball bearing |
| 5 | Thrust ball bearing |
| 6 | Deep groove ball bearing |
| 7 | Angular contact ball bearing |
| 8 | Thrust cylindrical roller bearing |
| N | Cylindrical roller bearing |
The size series code is composed of the width (height) series code and the diameter series code of the bearing. The diameter series code of the radial bearing is divided into: 7, 8, 9, 0, 1, 2, 3, 4. In this order, the outer diameter of the bearing with the same inner diameter gradually increases. The width series code is divided into 8, 0, 1, 2, 3, 4, 5, 6. They can be combined with any diameter series code, and the width size will gradually increase in this order. The height series of thrust bearings corresponds to the width series of radial bearings, which are 7, 9, 1, 2, etc., and the height size increases.
The width series code of the standard radial ball bearing is omitted, and the bearing code is expressed in 4 digits. The width series code is also omitted for cylindrical roller bearings with a width series code of 0.
| Bearing Size Series Code | ||||||||||||
| Diameter series code | Radial bearing | Thrust bearing | ||||||||||
| Width series code | Height series code | |||||||||||
| 8 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 9 | 1 | 2 | |
| Size series code | ||||||||||||
| 7 | - | - | 17 | - | 37 | - | - | - | - | - | - | - |
| 8 | - | 08 | 18 | 28 | 38 | 48 | 58 | 68 | - | - | - | - |
| 9 | - | 09 | 19 | 29 | 39 | 49 | 59 | 69 | - | - | - | - |
| 0 | - | 00 | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 90 | 10 | - |
| 1 | - | 01 | 11 | 21 | 31 | 41 | - | - | 71 | 91 | 11 | - |
| 2 | 82 | 02 | 12 | 22 | 32 | 42 | - | - | 72 | 92 | 12 | 22 |
| 3 | 83 | 03 | 13 | 23 | 33 | - | - | - | 73 | 93 | 13 | 23 |
| 4 | - | 04 | - | 24 | - | - | - | - | 74 | 94 | 14 | 24 |
| 5 | - | - | - | - | - | - | - | - | - | 95 | - | - |
| Bearing Inner Diameter Code | |||
| Bearing nominal inner diameter (mm) | Bearing inner diameter code meaning | Example | |
| 0.6~10 （(non-integer） | The inner diameter is directly expressed in millimeters, separated from the size series code by a slash "/". | 618/1.5, d=1.5mm | |
| 1~9 （integer） | The inner diameter is directly expressed in millimeters. For deep groove ball bearings and angular contact ball bearings of diameter series 7, 8, and 9, the inner diameter and size series code are separated by a slash "/". | 625, d=5 mm 618/5, d=5 mm | |
| 10~17 | 10 | 00 | 6000，d=10 mm |
| 12 | 01 | ||
| 15 | 02 | ||
| 17 | 03 | ||
| 20~480 （Except 22, 28, 32） | The quotient of the nominal inner diameter divided by 5, the quotient is the unit digit, add "0" to the left of the quotient, such as 08. | 23208，d=40 mm | |
| 22、28、32 | Directly express the nominal inner diameter in millimeters, separate the single size series with a slash "/" | 62/22，d=22 mm | |
| Greater than and equal to 500 | Directly express the inner diameter in millimeters (up to three decimal places after the decimal point), and separate it from the size series code with a slash "/" | 230/500， d=500 mm | |
| Non-standard inner diameter bearings | Non-standard inner diameter bearings are not expressed by any size code, but are directly expressed in millimeters (up to three decimal places after the decimal point, separated from the basic model with a slash. | 6020/15.375， d = 15.375 mm | |
The supplementary code of the bearing consists of a prefix code and a suffix code. The prefix code indicates the parts of the entire set of bearings, and can also indicate a variant design of the bearing. The suffix code indicates more, such as the internal structure change code, the external structure change code, the seal and dust ring change code, the cage material and structure change code, the tolerance grade change code, the clearance grade change code, etc.
The prefix code of a bearing indicates the parts of a complete set of bearings, and can also indicate a bearing variant design. It refers to the code added before the basic code of the bearing to indicate certain special designs, materials, processes or applications of the bearing. The specific prefix code may vary depending on the bearing manufacturer, but common prefix codes may include the following:
| Prefix Code | Prefix Code Meaning |
| F | Radial ball bearing with flanged outer ring |
| AR | Ball and cage assembly |
| K | Roller and cage assembly for radial or thrust cylindrical roller bearing |
| L | Separable inner or outer ring of separable bearing |
| R | Bearing without separable inner or outer ring |
| WS | Thrust cylindrical roller bearing shaft washer |
| GS | Thrust cylindrical roller bearing seat washer |
Suffix codes are used to indicate bearing models or variants that have different structures and/or other characteristics from the basic design. Suffixes are divided into several groups.
| Internal Structure Change Code | |
| Suffix code | Suffix code meaning |
| A | (1) Angular contact ball bearings - contact angle of 30° (2) Double-row angular contact bearings or deep groove ball bearings without ball loading notches (3) Deep groove ball bearings without flanges on the rings |
| B | (1) Angular contact ball bearings - contact angle is 40° (2) Tapered roller bearings, contact angle becomes larger |
| C | (1) Angular contact ball bearing - contact angle is 15° (2) C-type spherical roller bearing |
| D | Split bearings |
| E | Reinforced. Improved internal design, increased bearing load capacity |
| AC | Angular contact ball bearings - contact angle is 25° |
| CA | CA type spherical roller bearings |
| CC | CC type spherical roller bearings |
| CAB | CAB type spherical roller bearings |
| External Structure Change Code | |
| Suffix code | Suffix code meaning |
| G | Universally paired single row angular contact ball bearings or deep groove ball bearings. When arranged face to face, back to back or in series in the same direction, there is a certain pre-installation preload in the bearing. GA--light preload GB--medium preload GC--heavy preload |
| K | Conical hole, taper 1:12 |
| K30 | Conical hole, taper 1:30 |
| X | (1) One or more of the bearing's external dimensions have been modified to conform to ISO standards (2) Cylindrical rolling surfaces (support roller bearings, cam follower bearings) |
| R | Bearing with a retaining flange on the outer ring |
| N | Bearing with a retaining groove on the outer ring |
| NR | Bearing with a retaining groove and retaining ring on the outer ring |
| U | Externally self-aligning thrust ball bearing with self-aligning seat washer |
| DC | Double-row angular contact ball bearing, cool outer ring |
| DH | One-way thrust bearing with two seat rings |
| DS | One-way thrust bearing with two shaft rings |
| N1 | The edge of the outer ring of the bearing has a positioning notch (for bearing normal positioning O) |
| N2 | The edge of the outer ring of the bearing has two radially symmetrical positioning notches (for bearing normal positioning) |
| N4 | N+N2, the positioning notch and retaining groove are on opposite sides |
| N6 | N+N2, the positioning notch and retaining groove are on the same side |
| WB | Wide inner ring bearing |
| WC | Wide outer ring bearing |
| Seals And Dust Shield Change Code | |
| Suffix code | Suffix code meaning |
| RZ | Bearing with rubber seal on one side (non-contact type) |
| 2RZ | Bearing with rubber seal on both sides (non-contact type) |
| RS | Bearing with rubber seal on one side (contact type) |
| 2RS | Bearing with rubber seal on both sides (contact type) |
| LS | Bearing with rubber seal on one side (contact type, no groove on the ferrule) |
| 2LS | Bearing with rubber seal on both sides (contact type, no groove on the ferrule) |
| Z | Bearing with metal dust cover on one side |
| 2Z | Bearing with metal dust cover on both sides |
| Cage Material And Structure Change Code | |
| Suffix code | Suffix code meaning |
| F | Steel, ductile iron or powdered iron solid cage F1: Carbon steel F2: Graphite steel F3: Ductile iron F4: Powdered iron |
| Q | Bronze solid retainer Q1: Aluminum-iron-manganese bronze Q2: Silicon-iron-zinc bronze Q3: Silicon-nickel bronze Q4: Aluminum bronze |
| M | Brass solid cage |
| H | Self-locking pocket cage |
| J | Steel stamping cage |
| Y | Brass stamping cage |
| L | Light alloy solid cage |
| T | Fiber-reinforced phenolic resin cage |
| TN | Engineering plastic injection molded cage TN1: Nylon TN2: Polysulfone TN3: Polyimide TN4: Polycarbonate TN5: Polyoxymethylene |
| W | Welding cage |
| D | Carbonitriding cage D1 carburizing cage D2 nitriding cage" |
| C | Plated cage C1: Silver plated |
| V | Full complement of rolling elements (without cage) |
| Tolerance Grade Change Code | |
| Suffix code | Suffix code meaning |
| P0 | The tolerance grade conforms to the international standard ISO 0, which is omitted in the code and not indicated. |
| P6 | The tolerance grade conforms to the international standard ISO 6. |
| P6X | The tolerance grade conforms to the international standard ISO 6X tapered roller bearing. |
| P5 | The tolerance grade conforms to the international standard ISO 5. |
| P4 | The tolerance grade conforms to the international standard ISO 4. |
| P2 | The tolerance grade conforms to the international standard ISO 2 (excluding tapered roller bearings). |
| SP | The dimensional accuracy is equivalent to 5, and the rotation accuracy is equivalent to 4 (double-row cylindrical roller bearings). |
| UP | The dimensional accuracy is equivalent to 4, and the rotation accuracy is higher than 4 (double-row cylindrical roller bearings). |
| Clearance Change Code | |
| Suffix code | Suffix code meaning |
| C1 | Group 1 with clearance in accordance with the standard |
| C2 | Group 2 with clearance in accordance with the standard |
| C0 | Group 0 with clearance in accordance with the standard, omitted in the code and not indicated. |
| C3 | Group 3 with clearance in accordance with the standard |
| C4 | Group 4 with clearance in accordance with the standard |
| C5 | Group 5 with clearance in accordance with the standard |
The above are some of the suffix codes. In fact, there are many more suffix codes, such as bearing vibration related, paired supply related, maximum temperature related, grease related, oil injection related, etc. It is a huge project to fully grasp all the codes of bearings.
If it is not unsure, people can ask an expert or manufacturer to avoid making mistakes when choosing.
