The symbol of a bearing consists of a main and an additional symbols.

Basic conditional The designation defines the following characteristics of the bearing:

• bearing hole diameter;
• a series of diameters and a series of widths (heights);
• bearing type;
• design.

Brief List of Bearing Types(number 4 in the table):

• 0 - ball radial;
• 1 - ball radial spherical;
• 2 - radial roller with short cylindrical rollers;
• 3 - radial spherical roller;
• 4 - needle roller with long cylindrical rollers;
• 5 - radial roller with twisted rollers;
• 6 - angular contact ball;
• 7 - conical roller;
• 8 - ball thrust or thrust radial;
• 9 - roller thrust or thrust radial.

The designation of all the listed characteristics is made up of signs (numbers). The meanings of the numbers are determined by the places they occupy in the symbol (when reading from right to left):

• first and second – symbol of the bearing hole diameter (for bearings with a hole diameter of 10 mm or more);
• the third is a series of diameters;
• fourth - type of bearings;
• fifth and sixth – design;
• the seventh is a series of widths (heights).

Sum of true digital values , designated by the first, second, third and seventh digits, determines the overall dimensions of the bearing.

In the designation of bearings ranging from 20 mm to 495 mm inclusive, the first (1) and second (2) digits (on the right) of the symbol are the quotient of dividing the nominal hole diameter by five.

Example: Bearing 109 diameter series 1 With internal hole diameter 45 mm.

Example: Bearing 206 diameter series 2 With internal hole diameter 30 mm.

Bearings with bore diameter 22, 28, 32, 500 mm and more are indicated by a fraction, the denominator of which indicates the diameter of the internal hole, and the numerator - the remaining characteristics in the order established for all bearings.

Designations for the diameters of the inner holes of bearings from 10 to 17 mm are slightly different and correspond to the following table:

Example: 1000801 - Rolling bearing, radial ball, single row, basic design, series of diameters 8 with a hole diameter of 12 mm; 1000802 – a similar bearing with a hole diameter of 15 mm.

For bearings with an internal bore diameter of up to 10 mm, the first digit on the right indicates the size of the bearing bore diameter in millimeters.
Example: 19 – Rolling bearing, radial ball, single row, basic design, diameter series 1 with a hole diameter of 9 mm; 1000098 - Rolling bearing, radial ball, single row, basic design, series of diameters 9 with an internal hole diameter of 8 mm.

The following diameters of the inner bore of the bearings: 0.6; 1.5; and 2.5 mm are indicated by a fraction. If the bearing bore diameter is expressed fractional number, except for values ​​0.6; 1.5 and 2.5, then it has a designation of the hole diameter rounded to a whole number, in this case in its symbol the number 5 should be in second place.
Example: 56 – Rolling bearing, radial ball, single row with a hole diameter of 6.35 mm (1/4”).

Bearings that are non-standard in terms of outer diameter or width are designated in third place by the number 7 or 8. Non-standard bearings in terms of internal diameter or width are designated in second place by number 6 or 7 (this is true for bearings with an internal hole with a diameter of up to 10 mm).

Bearing type designation

The bearing type is indicated by the fourth number from the right.

* The number “0” is indicated if the symbol consists of five or more digits

** Some new designs have alphanumeric designations

Plain bearings

• Plain bearings for moving joints

• Plain bearings for fixed joints

The designs of each of the 10 types of bearings can be expressed through a combination of two numbers from 00 to 99, located in the 5th and 6th places of the main symbol. The design of the bearing, indicated by the numbers 00, is indicated only if there is a seventh significant digit.

Additional symbols are placed both on the left (separated by a hyphen) and on the right (must begin with capital letter) from the main symbol.

Additional bearing designations located to the left of the main designation

• Bearing clearance and preload
• Bearing frictional moment
• Bearing accuracy class
• Performance category

Bearing accuracy classes

The following bearing accuracy classes exist:

0, 6, 5, 4, 2, T- roller and ball radial and ball angular contact bearings;
0, 6, 5, 4, 2 - thrust and thrust radial bearings;
6Х*, 6, 5, 4, 2- tapered (roller) bearings (* - accuracy class 6X is indicated by one sign “ X”).

0 higher accuracy class 7 And 8 accuracy classes. Bearings 7 And 8 accuracy class are used in non-critical units.

0 accuracy class is not indicated.

To designate bearings that are subject to increased precision requirements, the letter is used "U". Example : 6U-7612

Designation of radial clearance

In the additional designation of the bearing, the radial clearance group is placed to the left of the accuracy class designation.

Example: 70- 207 , Where number 7 denotes the radial clearance group of the bearing, the number 0 – indicates the accuracy class bearing 207. The normal radial clearance group is not indicated in the bearing designation.

Additional requirements for the bearing in terms of radial clearance are indicated by the letter N.
Example: Н0-42207М , where the letter N is the designation of an additional (special) radial clearance group, the number 0 – designation of the bearing accuracy class 42207M.

Designation of the standard friction moment

The designation of the friction moment (rate) of the bearing is carried out by a number that corresponds to the number of the corresponding row of the rate of friction moment and is placed before the designation of the radial clearance of the bearing. In this case, when designating angular contact and radial single-row bearings with radial clearance corresponding to the normal group, the letter is placed in place of the designation of the radial clearance of the bearing M.

Example: 125-204 – rolling bearing, radial ball, single row 204 , accuracy class 5 , with radial clearance according to the group 2 , with the moment of friction - 1 (first row); 4M6-1000801– rolling bearing, radial ball, single row 1000801 , accuracy class 6 , with radial clearance - normal group, the friction moment corresponds to the fourth row.

Bearings of special assembly, with small radial clearances, are indicated by additional symbols: NT And WELL. Designation NT means reduced rotation accuracy and seat sizes; designation WELL– means only reduced bearing rotation accuracy.
Example: NT19Yu; NT25; NU202 Yu

Bearing category designation

In accordance with GOST 520-2011, depending on additional technical requirements. requirements there are three categories of bearings:

1. Category A- bearings 5, 4, 2, T accuracy classes;
2. Category B- bearings 0.6X*, 6.5 accuracy classes (* - additional requirements are taken into account);
3. Category C- bearings 8 , 7, 0, 6 accuracy classes;

   Category designations A And IN indicate:

• Before designating the bearing clearance, provided that there are no additional requirements for the standard friction torque and a group of clearances different from the normal one. Example: A25-203 ;
• Before designating the accuracy class of the bearing, provided that there are no additional requirements for the standard friction torque and a group of clearances different from the normal one. Example: A25-100 ; while for bearings
  the normal accuracy class is indicated by the number 0 . Example: B0-207

Additional bearing designations located to the RIGHT of the main designation

Bearing designations located to the left of the main designation:

• Design differences;
• Brand of material;
• Brand of lubricant used in sealed bearings;
• Special technical requirements;
• Noise requirements;
• Special temperature requirements;

Temperature conditions of bearings

Designation of bearing noise standards

The bearing noise level is indicated by the letter Sh with digital index ( Ш1, Ш2, Ш3, Ш4, Ш5…). As the digital index increases, the noise requirements become more stringent, and the level of bearing vibration decreases accordingly. Letter “ Sh” with a digital index is indicated to the right of the main symbol of the bearing following the designation of design differences ( TO) and separator material ( D, L, E, B) or ring material ( Yu, X, R).

• Example: 5-8320LSh1 , Where 5 - accuracy class of single row thrust bearing 8320 , L– brass separator, Ш1– designation of the noise level of the bearing.

Designation of the grease used in the bearing

Closed bearings use grease; additional designations depending on the lubricant used in the bearing are given in the table:

There are two main types of bearing designations: Russian - according to the state standard, and European - adopted in Western countries. Here we take a closer look at our designation system for rolling bearings.

A complete bearing marking consists of three parts:

• base, consisting of 2 to 7 digits (example: 5-1080094 yuts2), zero values ​​are omitted;
• a prefix separated from the base by a hyphen "-" (example: 5m4 -2076084ep);
• a suffix, which must begin with a letter, can be separated from the base by a space (example: 26-2000083yu5tp).

The designation of bearings with an internal diameter of less than 10 mm is slightly different from larger diameters. Let's decipher all the elements of the designation.

Inner diameter up to 10 mm

Excluding bearings with an internal diameter of 0.6; 1.5; 2.5 mm (they are indicated by a fraction).

Decoding the base

1. Width series
2. Design features
3. Design features
4. Bearing type
5. Digit 0
6. Diameter series
7. Inner ring diameter

Prefix on the left

The prefix may include Arabic numerals, letters of the Russian or Latin alphabets. It characterizes the manufacturing quality of the bearing.

1. A, B, C - designation of bearing categories
2. Numbers from 1 to 9 - designation of rows of friction moment
3. Designation of groups of radial clearances:
   • 0, 1, 2, normal, 3, 4, 5, 6, 7, 8, 9 according to GOST 24810
   • 6, normal, 7, 8 according to OSTVNIPP.006-00
   • 0, 1, 2, 3, 4 according to RTM 37.006.309
4. Accuracy classes according to GOST 520:
   • 8, 7, normal, (0), 6, 5, 4, T, 2

Suffix on the right

Characterizes the material of bearing parts, the brand of grease, as well as a number of special requirements and characteristics. The number after the letter in the designation suffix indicates the execution number.

1. Bearing element material:
   • Yu, Yu1, Yu2 ... some of the elements or all the elements are made of stainless steel
   • X, X1, X2 ... rings or rolling elements made of case-hardened steel
   • H, H1, H2 ... rings or rolling elements made of modified heat-resistant steel
   • 3, 31, Z2 ... bearing parts made of ShKh steel with alloying additives (calcium, cobalt, etc.)
   • P, P1, P2 ... bearing parts made of heat-resistant steel
   • I, Ya1, Ya2 ... bearing parts made of rare materials (ceramics, glass, etc.)
   • G, G1, G2 ... ferrous metal separator
   • B, B1, B2 ... tin-free bronze separator
   • D, D1, D2... aluminum alloy separator
   • L, L1, L2 ... brass separator
   • P, P1, P2 ... separator made of plastic materials
2. K, K1, K2 ... designation of design changes
3. U, U1, U2 ... special technical requirements for roughness, coatings, etc.
4. T, T1, T2 ... bearing ring release temperature
5. C1, C2, C3 ... types of lubricants for closed bearings
6. Ш, Ш1, Ш2 ... noise level requirement
7. M, M1, M2... rollers with modified profile

Inner diameter greater than 10 mm

In addition to bearings with hole diameters 22; 28; 32 and 500 mm (indicated by a fraction).

Decoding the base

1. Width series
2. Design features
3. Design features
4. Bearing type
5. Diameter series
6. Inner ring diameter
7. Inner ring diameter