INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE

STANDARD

(ISO 15241:2012, UT)

ISO 15241 - 2014

Official publication

Preface

The goals, basic principles and basic procedure for carrying out work on interstate standardization are established by GOST 1.0-92 “Interstate standardization system. Basic provisions" and GOST 1.2-2009 "Interstate standardization system. Interstate standards. rules and recommendations for interstate standardization. Procedure for development, adoption, application, updating and cancellation"

Standard information

1 PREPARED by the Limited Liability Company "Engineering Center EPK" (LLC "IC EPK") on the basis of its own authentic translation into Russian of the international standard specified in paragraph 5

2 INTRODUCED by the Technical Committee for Standardization TC 307 “Rolling Bearings”

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification by correspondence (protocol dated August 29, 2014 No. 69 - P)

4 By Order of the Federal Agency for Technical Regulation and Metrology dated September 8, 2014 No. 1009-st, the interstate standard GOST ISO 15241-2014 was put into effect as a national standard of the Russian Federation on January 1, 2016.

5 This standard is identical to the international standard ISO 15241:2012 Rolling bearings - Symbols for physical quantities.

The international standard ISO 15241 was developed by the Technical Committee for Standardization ISO/TC 4 “Rolling bearings” of the International Organization for Standardization (ISO).

Translation from English (ep).

Official copies of the international standard, on the basis of which this interstate standard has been prepared, and the international standards to which references are given, are available at the Federal Agency for Technical Regulation and Metrology.

Information on the compliance of interstate standards with reference international standards is given in Additional Appendix DA

Degree of compliance - identical (UT)

Information about changes to this standard is published in the annual information index “National Standards”, and the text of changes and amendments is published in the monthly information index “National Standards”. In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly information index “National Standards”. Relevant information, notifications and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

© Standardinform. 2015

8 of the Russian Federation, this standard cannot be fully or partially reproduced, replicated and distributed as an official publication without permission from the Federal Agency for Technical Regulation and Metrology

INTERSTATE STANDARD

Rolling bearings DESIGNATIONS OF PHYSICAL QUANTITIES

Rolling bearings Symbols for physical quantities

Date of introduction - 2016-01-01

1 area of ​​use

This standard establishes designations for physical quantities (dimensions, dimensional deviations, accuracy, load capacity, service life, etc.) in the field of rolling bearings. These designations are intended for use in standards and in regulatory and technical documentation for rolling bearings, and they can also be used in other printed materials, such as reference books, drawings, and reference publications.

2 Normative references

The following reference documents are required for the application of this standard. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 281:2007 Rolling bearings - Dynamic load ratings and rating life

ISO 1132-1:2000 Rolling bearings - Tolerances - Part 1: Terms and definitions

ISO 5593:1997 Rolling bearings - Vocabulary

ISO 80000-1:2009 Quantities and units - Part 1: General

ISO 80000-2:2009 Quantities and units - Part 2: Mathematical signs and symbols to be used in the natural sciences and technology

Note - When using this standard, it is advisable to check the validity of the reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or using the annual information index “National Standards”, which was published as of January 1 of the current year, and according to the releases of the monthly information index “National Standards” for the current year. If the reference standard is replaced (changed), then when using this standard one should be guided by the replacing (changed) standard. If the reference standard is canceled without replacement, then the provision in which a reference to it is given, applies to the extent not affected by this reference

3 Terms and definitions

This standard applies the terms and definitions in ISO 281, ISO 1132-1 and ISO 5593.

4 Designations of physical quantities

4.1 Notation principles

The following basic rules apply to this standard.

Official publication

The notation system basically follows the rules of ISO 80000-1 and ISO 80000-2 1 2 . The designations of physical quantities used in the field of rolling bearings are specified as for quantities in physics. Thus, notations for dimensionless quantities such as coefficients, factors, and constants are also included. Mathematical variables such as probability (n) are also included.

Subscripts should not be used for subscripts. For example, the subscript letters "dmp" from the designation should be printed at the same level in one

font size. Form I

Other subscripts, roman font

Superscripts should not be used

Subscript representing quantity, italics

Figure 1 - Principle of designation

4.2 Construction of the notation

Physical quantities must be designated either by a basic designation, which is a separate letter of the Latin or Greek alphabet, or by a basic designation with a subscript consisting of one or more letters of the Latin or Greek alphabet or Arabic numerals. A period is not placed at the end of the designation.

4.3 Basic designations

Basic symbols represent physical quantities. Sometimes one basic symbol can represent different physical quantities. The main designations are given in Table 1.

4.4 Subscripts

Subscripts added to the main designation modify the main physical quantity in terms of properties, features, numbering, etc. The subscripts used are shown in Table 2. Subscripts representing physical quantities are printed in the same way. as well as basic designations (for example Us 1 . D~.).

4.5 Symbol printing styles

Basic designations are printed in italics (oblique). Subscripts representing physical quantities are printed in italics. Numerical subscripts and other symbols are printed in roman characters, such as e (referring to outer ring), g (referring to radial), d (referring to hole). All subscripts must be the same font size.

Examples" 1

1 In the notation Vam P (variability of mean bore diameter), the subscript “d” means “bore diameter” and is printed in italics. Subscript "t". meaning “average,” and the subscript “p,” meaning “in the unit plane,” are printed in roman font. All subscripts are in the same font size.

2 In the designation S a (perpendicularity of the end of the inner ring relative to the hole), the subscript “b” means “relative to the surface of the hole” and is printed in roman font.

5 Classification of designations of physical quantities

Tables 3-10 show symbols related to the following groups of physical quantities:

Dimensions and geometric characteristics of bearings and rings (Table 3);

Dimensions and deviations of bearings and rings (Table 4);

Rotation accuracy of bearings and rings (Table 5);

Geometric characteristics and deviations of subassemblies (Table 6);

Dimensions and deviations of rolling elements (Table 7);

Geometric characteristics of shafts and housings (Table 8):

Bearing loads and load capacities (Table 9);

Bearing life (table 10).

6 Definitions of physical quantities

Definitions of physical quantities are in accordance with ISO 5593 and ISO 1132-1. In some cases, the definitions of physical quantities are consistent with other standards relevant to rolling bearings.

7 Using square brackets

Two closely related physical quantities and their descriptions in Tables 3-10 are grouped into one article if these physical quantities are defined in the same text, with the exception of a few words. Words that should replace those. that they are preceded, to obtain a different meaning, are placed in square brackets, i.e. “()”.

8 Designations and descriptions of physical quantities

Symbols and descriptions of physical quantities used in the field of rolling bearings are given in Tables 1-10.

Table 1 - Basic designations

Index Basics designation Physical quantity case width tight ring height outer ring width free ring height outside diameter Geometric characteristic diameter of an outer or free ring element, excluding the diameter of the raceway diameter of bearing seat element hole diameter diameter of the inner or tight ring element, excluding the diameter of the raceway outer ring raceway diameter inner ring raceway diameter thread designation eccentricity body center height bolt hole center distance body or roller length

Index	Basic designation	Physical quantity
Geometric characteristics		thread length
		bolt hole geometric characteristics
		coordinate, chamfer radius
		radius (gutter)
		thickness (thrust bearing ring)
		width (assembled)
Deviation, accuracy		radial runout
		variation in thickness
		axial runout
		thickness difference (thrust bearing)
		impermanence
		deviation from nominal value
	lifting capacity
		internal clearance
		number of rows of rolling elements
		number of rolling bodies in a row
		contact angle or slope angle

Table 2 - Subscripts

Index Interlinear Description effective average upper limit Basic lower limit plane in which the measurement is taken singular or real static (zero) Direction radial letter identifier when more than one diameter is applied to tightly mating parts (e.g. shaft housing, gasket, bushing) separator Part, element or feature on the outer surface along the hole surface outer or loose ring inner or tight ring rolling body numeric identifier when more than one diameter is used. of the same width or height, preferably to mating parts (e.g. free self-aligning ring, spherical seat ring, circlip, extension collar) adjusted time watch modified probability of failure corresponding to (100 - n)% reliability

Note - Regarding subscripts, see 4 4

Table 3 - Dimensions and geometric characteristics of bearings and rings

Designation Physical quantity Clause in ISO 5593 height of the center of the spherical surface distance defining the position of the bearing load center bearing width inner ring width tight ring height axial measurements of the inner [tight] ring axial measurements of parts mainly associated with the inner [tight] ring snap ring groove width outer ring width free ring height outer ring thrust flange width axial measurements of the outer [loose] ring axial measurements of parts mainly associated with the outer [free] ring bearing outer diameter outer diameter of outer [free] ring outer diameter of thrust ring outer diameter of the outer ring thrust flange diameter of outer [free] ring element (excluding raceway diameter) bearing bore diameter hole diameter of inner [tight] ring thrust ring hole diameter nominal thread diameter (external and internal) do 1. diameter of the part predominantly associated with the thread diameter of the inner [tight] ring element (excluding raceway diameter) outer diameter of ball set outer diameter of roller set spring ring section height ball set hole diameter roller set hole diameter snap ring thickness thread designation number of rows of rolling elements thread length axial dimension related to thread chamfer coordinate radius of the outer [free] ring groove radius of the groove of the inner [tight] ring chamfer coordinate thrust ring thickness bearing width (assembled) bearing mounting height

* Thread designation includes the designation of the thread shape, nominal diameter and, if necessary, thread pitch, for example M16 x1.5.

Table 4 - Dimensions and deviations of bearings and rings

Designation Physical quantity nominal bearing width nominal inner ring width nominal height of tight ring average inner ring width average height of tight ring unit inner ring width unit height of tight ring nominal bearing width nominal outer ring width nominal free ring width average outer ring width average free ring width unit outer ring width unit free ring width nominal width of the thrust flange of the outer butt unit width of outer ring thrust flange nominal outside diameter average outer diameter average outer diameter in a single plane unit outer diameter single outer diameter in a single plane nominal bore diameter average hole diameter average hole diameter in a single plane single hole diameter unit diameter of hole in unit plane axial internal clearance radial internal clearance nominal chamfer coordinate chamfer unit coordinate radial unit coordinate of the chamfer axial unit coordinate of the chamfer largest unit coordinate of the chamfer smallest unit coordinate of chamfer tolicin thrust ring nominal (mounting) width of the bearing nominal bearing height actual (mounting) width of the bearing actual bearing height Inconsistency of the width of the inner ring inconsistency of the height of the tight ring inconsistency of outer ring width inconsistency of free ring height

Designation Physical quantity inconsistency of the width of the thrust flange of the outer ring variability of average outer diameter variability of outer diameter variability of outer diameter in a single plane variability of average hole diameter hole diameter variability variability of hole diameter in a single plane nominal contact angle draft angle (half cone angle) of the inner ring hole deviation of unit width of inner ring deviation of a single height of a tight ring outer ring unit width deviation deviation of single free ring height deviation of the unit width of the outer ring thrust flange deviation of average outer diameter deviation of the average outer diameter in a single plane deviation of a single outer diameter deviation of a single outer diameter of the outer ring thrust flange deviation of average hole diameter deviation of the average hole diameter in a single plane deviation of single hole diameter deviation of the actual (mounted) width of the bearing deviation of actual bearing height

Table 5 - Rotation accuracy of bearings and rings

Designation Physical quantity difference in thickness of the outer ring raceway relative to the outer surface radial runout of the outer ring of the bearing in the assembly -_22_ difference in thickness of the inner ring raceway relative to the hole radial runout of the inner race of the bearing assembly asynchronous radial runout of the inner ring of the bearing assembly’ perpendicularity of the outer surface of the outer ring relative to the end perpendicularity of the outer surface of the outer ring relative to the supporting end of the thrust flange perpendicularity of the end of the inner ring relative to the hole perpendicularity of the inner ring hole relative to the end

The same designation system rules apply in GOST 8 417-2002. which is recommended to be used instead of ISO 80000-1 and ISO 80000-2

In these examples (due to the expediency of illustrating fonts), bold italics are not used, which are usually used to highlight examples 2

diameter series have the following values: 8,9,0,1,7,2,3,4, (listed in order of increasing outer size of the bearing diameter, while the inner diameter remains unchanged)

4. hole diameter

The last 2 digits indicate the bearing size code, multiplying this number by 5 to obtain the bore diameter in mm. But there are exceptions:

- For bearings with a bore diameter of less than 10 mm or 500 mm and above, the bore diameter is usually specified in millimeters and is not coded. The size designation is separated from the rest of the bearing designation by a slash, for example: 618/8 (d = 8 mm) or 511/530 (d = 530 mm).This also applies to standard bearings that comply with ISO 15:1998 and have a bore diameter of 22, 28 or 32 mm, for example: 62/22 (d = 22 mm).

Bearings with bore diameters 10, 12, 15 and 17 mm, have the following size codes:
00 = 10 mm
01 = 12 mm
02 = 15 mm
03 = 17 mm

Hole diameters that deviate from the standard are never coded and are indicated in millimeters to three decimal places. This hole diameter designation is part of the main designation and is separated from it by a slash, for example, 6202/15.875 (d = 15.875 mm = 5/8 inch).

Prefix decoding

AR Separator assembly with balls or rollers. G.S. Loose ring of a cylindrical thrust roller bearing. IR Inner ring of a radial bearing. K Set of thrust cylindrical rollers with cage Inner ring assembly with cage and rollers or outer ring of inch tapered roller bearing meeting ABMA standard (disassembled). L Separate inner or outer ring of a dismountable bearing. OR Outer ring of a radial bearing. R A set of inner or outer ring with rollers (and cage) of a separable bearing. W Stainless steel deep groove ball bearing W.F. Stainless steel deep groove ball bearing with a thrust flange on the outer ring. W.S. Tight ring of cylindrical thrust roller bearing. ZE Bearing with SensorMount® function.
Decoding the suffix (the one on the right) - Internal design A, B, C, D, E - the internal design has been changed with the main dimensions unchanged. - Design Features A.C. Single row angular contact ball bearing with a contact angle of 25°. ACD Single row angular contact ball bearing of improved design with a contact angle of 25°. ADA Wide grooves for a retaining ring on the outer ring, a split inner ring, the parts of which are connected by a retaining ring. BE Single row angular contact ball bearing with 40° contact angle and optimized internal design. Bxx(x) The letter B in combination with a two- or three-digit number denotes a variant of the standard design that cannot be identified by conventional suffixes. CD Single row angular contact ball bearing of improved design with a contact angle of 15°. CC C-type spherical roller bearing with improved roller guidance. CA, CB, CC Axial clearance group of single row angular contact ball bearings for universal pair installation (tandem, O- or X-shaped). With an O- or X-shaped arrangement in the pre-installation state, they have a small (SA), normal (SV) or increased (SS) axial clearance. 2F Oil flinger rings on both sides for Y bearings. 2FF Fluff seal rings on both sides for Y bearings. G Normal axial clearance for single row angular contact ball bearings for universal pair installation (in O- or X-shape). G.A., G.B., G.C. Axial preload group of single row angular contact ball bearings for universal pair installation (tandem, O- or X-shaped). With an O- or X-shaped arrangement in the pre-installation state, they have a light (GA), medium (GB) or heavy (GC) axial preload. K Conical inner bore, taper 1:12. K30 Tapered inner bore, taper 1:30. L.S. LS type contact seal on one side of the bearing. 2LS LS type seals on both sides of the bearing. N Groove for the circlip on the outer ring of the bearing. NR Same as N, but complete with retaining ring. N2 Two locking grooves offset by 180° on the outer surface of the bearing outer ring. PP Contact seals on both sides of the support rollers. R.S. Contact seal made of polyurethane or rubber on one side of needle roller bearings. RS1 Reinforced rubber contact seal on one side of the bearing. 2RS1 RS1 type contact seals on both sides of the bearing. 2RS RS type contact seals on both sides of the needle roller bearing. RZ Reinforced rubber contact seal with reduced friction on one side of the bearing. 2RZ RZ type contact seals on both sides of the bearing. X Dimensions differ from the ISO standard or support rollers with a cylindrical outer surface. Z Protective metal washer (non-contact seal) on one side of the bearing. 2Z Z type protective metal washers on both sides of the bearing. ZN A Z-type protective metal washer on one side and a snap ring groove on the outer surface on the opposite side of the bearing. 2ZN Z type protective metal washers on both sides and a circlip groove on the outer surface of the bearing. ZNR ZN + retaining ring. 2ZNR 2ZN + retaining ring. - Separators F Machined cage made of steel or special cast iron. J Pressed steel sheet separator. T Machined cage made of PCB. L Machined light alloy cage. M Machined brass cage. MP Machined brass window type cage. R Molded cage made of glass-filled polyamide. TN Molded plastic separator. TN9 is a molded cage made of glass-filled polyamide. Y Pressed sheet brass cage. A Centering on the outer ring. IN Centering on the inner ring. No Centering on rolling elements. V Full complement bearing. VH Non-separable full complement bearing. - Accuracy class CLN Complies with ISO 6X accuracy class for metric tapered roller bearings (tighter width tolerance). CLO Complies with ISO accuracy class O for inch tapered roller bearings. CL3 Complies with ISO accuracy class 3 for inch tapered roller bearings. CL7A Standard accuracy class for tapered roller bearings used in pinion bearings. CL7C Special precision class of tapered roller bearings used in gear shaft bearings. P6 Dimensional accuracy and run-out correspond to ISO accuracy class 6. P5 Dimensional accuracy and runout correspond to ISO accuracy class 5 (more precisely P6). P4 Dimensional accuracy and runout correspond to ISO accuracy class 4 (more precisely P5). P4A Dimensional accuracy corresponds to ISO accuracy class 4, runout - ABEC accuracy class 9 according to the AFBMA standard. RA9A Dimensional accuracy and radial runout comply with ABEC 9 accuracy class according to the AFBMA standard. RA9V The dimensional accuracy corresponds to the ABEC 9 accuracy class according to the AFBMA standard, the runout is less than that of bearings of the PA9A accuracy class. SP Dimensional accuracy approximately corresponds to accuracy class P5, runout - to accuracy class P4. U.P. The dimensional accuracy approximately corresponds to the P4 accuracy class, the runout is less than that of bearings of the P4 accuracy class. - Internal clearance C1 The internal clearance in the bearing is less than C2. C2 The internal clearance in the bearing is less than normal. No Normal internal clearance NW The internal clearance in the bearing is greater than normal. C4 The internal clearance in the bearing is greater than NW. C5 The internal clearance in the bearing is greater than C4. When combined with suffixes indicating the accuracy class, the letter C is omitted. Example: P5+C3 = P53. - Vibrations QE5 Special quality bearings for electric motors; dimensional accuracy and runout correspond to accuracy class P6, low vibration level. QE6 Standard quality bearings for electric motors. Q05 Particularly low level of vibration peaks. Q06 The vibration peak level is less than normal. Q5 Particularly low vibration level (replacement of C7 version). Q6 The vibration level is less than normal (replacement of version C6). - Working temperature(thermal stabilization) S0 - up to 150°С S1 - up to 200°C S2 - up to 250°C S3 - up to 300°C S4 - up to 350°C - Relubrication W Without ring groove and lubrication holes in the outer ring. W20 Three lubrication holes in the outer ring of the bearing. W26 Six lubrication holes in the bearing inner ring. W33 An annular groove and three lubrication holes in the outer ring of the bearing. W33X An annular groove and six lubrication holes in the outer ring of the bearing. W513 Six lubrication holes in the inner ring, an annular groove and three lubrication holes in the outer ring. W518 Six lubrication holes in the inner ring and three in the outer ring. W77 Lubrication holes W33 with plugs. AS Needle roller bearing with lubricant holes on the outer ring. The number following the letters AS indicates the number of holes. ASR Needle roller bearing with annular groove and holes for lubricant supply on the outer ring. The number following the letters ASR indicates the number of holes. IS Needle roller bearing with lubrication holes on the outer ring. The numbers following IS indicate the number of holes. ISR Needle roller bearing with an annular groove and lubrication holes on the outer ring. The numbers following the ISR indicate the number of holes. - Lubricants G __ __ - bearing filled with grease. The second letter indicates the operating temperature range of the lubricant, and the third letter indicates the grease used. The second letter has the following meanings: E anti-seize grease, F food compatible lubricant H, J high temperature grease, –20 to +130 °C, L low temperature grease, –50 to +80 °C, M medium temperature grease, –30 to +110 °C, W, X Grease for a wide temperature range, from –40 to +140 °C. W.T. Grease for a wide temperature range (-40 to +160 °C). The number after the three-letter grease code means that the fill level is different from the standard: numbers 1, 2 and 3 mean it is less than standard, numbers 4-9 mean it is more than standard. Other possible lubricant designations: VT143 Anti-seize grease with lithium hardener, consistency 2 on the NLGI scale for temperatures from -20 to +110°C (normal fill). VT378 Grease with aluminum hardener, consistency 2 on the NLGI scale for temperatures from -25 to +120°C (normal filling level). GJN Grease with polyurethane hardener, consistency 2 on the NGLI scale for temperatures from - 30 to + 150 ° C GХN Grease with polyurethane hardener, consistency 2 on the NGLI scale for temperatures from - 40 to + 150 ° C - Special purpose bearings V _ _ _ _ (_) - a combination of the letter V and a second letter denotes a group of characteristics, and the following three- or four-digit number denotes options that are not covered by standard designation suffixes. V.A. Designed for a specific application. VB Deviations of main dimensions. V.E. Deviations of external or internal parameters VL Coatings. VQ Quality and tolerances different from standard. VS Clearance and preload VT Lubrication. See VT143 and VT378 above VU Various additional features.

In the most general case, the number, designation and marking of a bearing are approximately the same thing, namely a combination of numbers (often also letters) that identifies a specific product.

Consists of a basic designation and possibly one or more additional ones:

The basic designation of a bearing consists of a combination of numbers (sometimes letters) in which its main parameters are encoded:

• size

Additional bearing designation, also consisting of letters and numbers, may indicate:

• execution
• design features
• special materials
• individual parts of the product

Only the basic designation without an additional one usually has the basic design of the bearing, for example, an open bearing - single-row radial ball (6), diameter series 2, width series 0, size code 7 (hole diameter 7 * 5 = 35 mm).

Additional designations before the base one are a prefix, after the base one a suffix. If additional There are several bearing designations, they are arranged in a certain order. For example, bearing E2.6207-2Z/C3 - E2 energy-saving, 6207 - see above, 2Z - protective washers on both sides, C3 - increased internal clearance.

The designation of standard bearings corresponds to dimensional standards such as ISO 15 and can be deciphered and used to order the same or similar product.

The designation of special bearings designed to meet individual requirements may not always be recognized. To buy the same bearing, you must either request it from the manufacturer, or find a reliable analogue, or make it yourself or order it based on the results of studying its dimensions and characteristics.

Bearing numbers

This is usually the name given to the digital part of a bearing designation according to ISO or GOST. The number of a standard bearing is usually its basic designation.

Bearing numbers, in the sense of shop drawing numbers, are often used to identify bearings that are specially manufactured for a specific customer by manufacturers such as SKF. At the same time, even knowing the numbers of such bearings, it is almost impossible to buy them, since their sale is prohibited under the contract between the equipment and bearing manufacturers.

Knowing only the bearing number, it is not always possible to order the same one, because it is not a complete designation, just like the marking.

Bearing markings

Rolling or sliding bearings are marked on their rings or seals by laser, chemical etching or any other method. The marking contains the bearing designation (in whole or in part), brand and country of origin.

The full bearing designation is sometimes not included entirely in the markings on the product itself, but it is always on its packaging and in accompanying documents. And, unfortunately, it is not always possible to reconstruct the full designation from the bearing markings.

Buy a bearing by designation

To buy a bearing by designation in BERG AB, please inform us in a letter to the address the exact designation of the bearing and your contact information. After processing your request, our technical manager will contact you.

Explanation of bearing designations - prefix, code, suffix

Basic bearing prefixes
E2 - Energy saving bearing
W - Stainless steel deep groove ball bearing

Rolling bearing codes
0 - double row angular contact balls
1 - self-aligning ball
2 - spherical roller, incl. persistent
3 - tapered roller bearings
4 - double row radial balls
5 - thrust ball
6 - single row radial balls
7 - single row angular contact balls
8 - cylindrical thrust roller bearings
C - CARB toroidal roller bearings
N - cylindrical roller bearings
QJ - ball with four-point contact
T - tapered roller bearings according to ISO 355

Basic bearing suffixes
A, B, C, D or E - modified internal design with standard basic dimensions
AC - Single row angular contact ball bearing with 25° contact angle
CV - Full complement cylindrical roller bearing with modified internal design
CS - Contact seal made of acrylonitrile butadiene rubber (NBR), reinforced with sheet steel, on one side of the bearing
2CS - CS contact seal on both sides
C3 - Increased internal clearance
F - Rolling element centered machined steel or cast iron cage
FA - Outer ring centered machined cage made of steel or cast iron
FB - Inner ring centered machined cage made of steel or cast iron
H - Pressed snap-on steel cage, hardened
HA - Case-hardened steel bearing or bearing parts. The numbers after HA mean:

• 0 bearing assembly
• 1 bearing ring – outer and inner
• 2 outer ring
• 3 inner ring
• 4 both rings and rolling elements
• 5 rolling elements (balls or rollers)
• 6 rolling elements and outer ring
• 7 rolling elements and inner ring

HB - Bearing or its parts hardened to bainite. Numbers after HB - see HA
HC - Bearing or its parts made of ceramic. Numbers after HC - see HA
HE - Bearing or its parts made of vacuum remelted steel. Numbers after HE - see HA.
HM - Bearing or its parts made of martensite-hardened steel. Numbers after HM - see HA
HN - Bearing or its parts with special surface heat treatment. Numbers after HN - see HA
HT - High temperature grease, -20…+130 °C
HV - Bearing or its parts made of hardenable stainless steel. Numbers after HM - see HA
J - Stamped steel cage, centered on rolling elements, non-hardened;
JR - Cage consisting of two riveted flat washers made of non-hardened steel
K – Bearing with tapered bore, taper 1:12
K30 – Bearing with tapered bore, taper 1:30
LHT - Grease for temperature range -40 to +140 °C
LS - Contact seal made of nitrile butadiene rubber (NBR) or polyurethane (AU), reinforced or not, on one side of the bearing
2LS - Contact seal, both sides
LT - Low temperature grease, -50…+80 °C
L4B - Bearing rings or rolling elements with special coating
L5B - Rolling elements with special coating
L5DA – Marking of bearings whose rolling elements have a special NoWear coating
L7DA - Bearing, the rolling elements and the inner ring raceway have a special NoWear coating
M - Machined brass cage, centered on rolling elements;
MA - Outer ring centered machined brass cage
MB - Inner ring centered machined brass ring cage
ML - Inner or outer ring centered one piece brass window type cage,
MP - Inner or outer ring centered solid brass cage, window style with pressed or drawn pockets
MR - Solid brass window type cage, centered on rolling elements
MT - Grease for medium temperatures, -30…+110 °C
N - Groove for the retaining ring in the outer ring
NR - Retaining ring and groove for it in the outer ring
N1 - There is one groove at the end of the outer ring for fixing
N2 - At the end of the outer ring there are two grooves for fixing at the ends of the diameter
P - Rolling element centered cast polyamide cage (PA 6.6), glass filled
P2 - ISO bearing accuracy class number 2
P4 - Accuracy class 4 ISO
P5 - Accuracy class 5 ISO
Q - Tapered roller bearing with optimized internal geometry and surface finish
R - Outer ring with flange
RS - Acrylonitrile butadiene rubber (NBR) contact seal, reinforced or not, on one side of the bearing
2RS - RS contact seal on both sides
RS1 - Contact seal made of acrylonitrile butadiene rubber (NBR), reinforced, on one side of the bearing
2RS1 - Contact seal RS1 on both sides of the bearing
RS2 - FPM contact seal, reinforced, on one side of the bearing
2RS2 - Contact seal RS2 on both sides
RSH - Acrylonitrile butadiene rubber (NBR) contact seal on one side of the bearing, reinforced
2RSH - Contact seal RSH on both sides
RSL - Low friction acrylonitrile rubber (NBR) seal on one side of the bearing, reinforced
2RSL - Low friction seal RSL on both sides
RZ - Low friction acrylonitrile rubber (NBR) seal on one side of the bearing, reinforced
2RZ - Low friction seal RZ on both sides
S0 - Stabilization of bearing rings for operating temperatures up to +150 °C
S1 - Stabilization of bearing rings for operating temperatures up to +200 °C
S2 - Stabilization of bearing rings for operating temperatures up to +250 °C
S3 - Stabilization of bearing rings for operating temperatures up to +300 °C
S4 - Stabilization of bearing rings for operating temperatures up to +350 °C
T - Rolling element-centered machined textolite cage
TB - Inner ring-centered window-type textolite cage
TH - Rolling element centered snap-on textolite cage
TN - Rolling element centered cast polyamide cage
TNH - Rolling element centered cast cage made of polyetheretherketone (PEEK), glass filled
TNHA - Outer Ring Centered Cast PEEK Cage, Glass Filled
TN9 - Rolling element centered cast polyamide cage (PA 6.6), glass filled
V - Full complement bearing
VA201, VA208, VA216, VA228 - Bearing for high temperatures
VA301, VA305 - Bearing for traction motors
VA3091 – Designation of bearings for traction motors with electrically insulating coating on the outer surface of the outer ring
VA405 - Bearing for vibration machines
VA406 - Bearing for vibrating machines, the hole of which is coated with fluoroplastic
VL0241 - Electrical insulating coating on outer ring outer surface
VL2071 - Electrical insulating coating on the outer surface of the inner ring
WT - Grease for a wide temperature range -40…+160 °C
W64 – Marking of bearings with Solid Oil antifriction filler
X - Basic dimensions differ from those regulated by the ISO standard
Y - Stamped brass cage, centered on the rolling elements;
Z - Sheet steel shield on one side of the bearing
2Z, ZZ - Protective washers made of sheet steel on both sides

The International Organization for Standardization has developed general requirements for basic dimensions:

• Metric radial rolling bearings - ISO 15:1998 standard (except tapered roller bearings);
• Metric radial tapered roller bearings - ISO 355:1977 standard;
• Metric thrust roller bearings - ISO 104:2002 standard;
• For other series, the “European” designation system is used.

Designation of bearing types

The bearing identification code is made up of a series of letters and numbers that have a specific meaning and is divided into three components, starting from left to right:

• The first part is the design of the bearing;
• The second part is the dimensional series of the bearing;
• The third part is the diameter of the bearing hole.

The first part of the symbol displays the structural form. This part is always indicated in numerical form, with the exception of cylindrical roller bearings and removable ring ball bearings.

The second part of the symbol indicates the type of bearing:

0 Angular contact ball bearings

1 Self-aligning ball bearings

2 Spherical roller bearings, spherical thrust roller bearings

3 Tapered roller bearings

4 Double row deep groove ball bearings

5 Thrust ball bearings

6 Single row deep groove ball bearings

7 Single row angular contact ball bearings

8 Cylindrical roller thrust bearings

N Cylindrical roller bearings (the letter “N” may be followed by one or two more letters to indicate the design of the thrust flanges of cylindrical roller bearings, e.g. NJ, NU, NUP)

QJ Four Point Contact Ball Bearings

The second part of the symbol displays the size series of the bearing: other dimensions of the bearing can be determined, more precisely the outer diameter and width, in accordance with the diameter of the hole. With the same hole and outer diameter, the bearing can have different widths. Therefore, we can roughly divide the combination into a series of diameters and a series of widths.

The series of diameters, like the series of widths, are designated by integers; both numbers create a dimensional series of bearings. Starting to define the designation from left to right, the first number indicates the series of widths, the second - the series of diameters. This combination is called a Size Series, and is preceded by a hole diameter code. If the bearing type provides only one width series, the width number is not indicated. The designation of the Dimensional Series will consist exclusively of a number containing a series of diameters.

The third part displays the diameter of the hole and includes two numbers with the following coding system:

00 = hole Ø 10 mm
01 = hole Ø 12 mm
02 = hole Ø 15 mm
03 = hole Ø 17 mm
04 = hole Ø 20 mm (more precisely 20: 5 = 04)
05 = hole Ø 25 mm (more precisely 25: 5 = 05)
... before:
96 = hole Ø 480 mm (more precisely 480: 5 = 96)

If the bearing bore diameter is equal to or greater than 500 mm, the portion of the symbol indicating the Size Series is separated by a slash (/) followed by the bore diameter in millimeters. Eg. 62/500. For a certain type of bearing, the first two parts of the designation remain unchanged, but the last part can be changed, more precisely the part that determines the bore diameter code. The unchanging part of the designation, which includes the design form and size series, is usually called the “bearing series”.

Bearing series

Type bearing	Series bearing	Designation types bearings	Dimensional series
Single row radial ball bearings	618	6	18
	619	6	19
	160	6	(0)0
	60	6	(1)0
	62	6	(0)2
	63	6	(0)3
	64	6	(0)4
Double row radial ball bearings	42	4	(2)2
	44	4	(2)3
Single row angular contact ball bearings	719	7	19
	70	7	(1)0
	72	7	(0)2
	73	7	(0)3
	74	7	(0)4
Double row angular contact ball bearings	32	(0)	32
	33	(0)	33
Ball bearings With four-point contact	QJ2	QJ1	(0)2
	QJ3	QJ1	(0)3
Self-aligning ball bearings	12	1	(0)2
	22	(1)	22
	13	1	(0)
	23	(1)	23
Single row cylindrical roller bearings	NU10	NU	10
	NU2	NU	(0)2
	NU22	NU	22
	NU32	NU	32
	NU3	NU	(0)3
	NU23	NU	23
	NU4	NU	(0)4
Conical roller bearings	329	3	29
	320	3	20
	330	3	30
	331	3	31
	302	3	02
	322	3	22
	332	3	32
	303	3	03
	313	3	13
	323	3	23
	239	2	39
Spherical roller bearings	230	2	30
	240	2	40
	231	2	31
	241	2	41
	222	2	22
	232	2	32
	213	2	03
	223	2	23
Persistent ball bearings	511	5	11
	512	5	12
	513	5	13
	514	5	14
	532	5	32
	533	5	33
	534	5	34
Double persistent shear bearings	522	5	22
	523	5	23
	524	5	24
Persistent spherical roller bearings	292	2	92
	293	2	93
	294	2	94

1 - Numbers in brackets are not included in the bearing series code designation
2 - Cylindrical roller bearings include NJ, NUP, N, NF and NU series

Bearing suffixes

Z- One-sided metal bearing protection washer

ZZ- Double-sided metal bearing protection washer

R.S.- One way rubber seal for bearing

2RS- Double sided rubber seal for bearing

N- Groove for the circlip on the outer ring of the bearing

NR- Groove and retaining ring on outer ring

M- Brass separator

M.A.- Brass cage centered on the outer ring

M.B.- Brass cage centered on the inner ring

TN- Reinforced polyamide separator

P6- Accuracy class corresponds to ISO 6

P5- Accuracy class corresponds to ISO 5

P4- Accuracy class corresponds to ISO 4

C2- A series of gaps is less than normal

C3- A series of gaps larger than normal

C4- Series of gaps greater than C3

C5- Series of gaps greater than C4

K- Tapered hole

In the modern world there are more than 1000 bearing manufacturers. Since they are an industrial product, their designation and classification are standardized in the international ISO system.

At the same time, many Russian manufacturers use the GOST standard system, which differs in the method of classifying bearings from the international ISO standard.

In the practice of our work, we often encounter situations when enterprise technologists switch from Russian bearings to imported ones. Or to Russian ones, but more modern, standardized according to ISO. As a rule, this happens when there is a desire to increase the overhaul life of equipment or reduce the risks of unexpected failure of machines and units.

Accordingly, when selecting replacement bearings, the question arises: how to determine the type of bearing in another standardization system.

To help specialists in purchasing departments and technologists of enterprises, we have compiled a comparative table of bearing standards (715 kB. PDF). You can download it for independent use in your practical activities.

Example

Just recently, one of our clients, a large industry company engaged in the production of leather goods, decided to increase the turnaround time for servicing its equipment fleet.

In particular, the client’s production uses ASG-12 machines, still made in the Soviet Union. As engineers say: “The machine is eternal, just change the spare parts.”

Until recently, the turnaround time for these machines was six months. Most often, replacement of bearings in the drives of sharpening mechanisms was required, since these are highly loaded units. It was decided to switch from domestic bearings to imported ones with a higher service life. During selection, it was necessary to determine the ISO designation of this type of bearings, since in the machine specification all parts were specified in the GOST standard.

As a result, bearings from the German manufacturer LFD from the middle price group were chosen as an alternative. They are marked 32314A according to ISO and are an analogue of Russian bearings marked according to GOST 7614.

Thanks to a change in bearing manufacturer, the overhaul period was increased from six months to 12 months. At the same time, the difference in price between previously used domestic bearings and LFD bearings was 30%.