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UDC 621.822
IS0
i N T E R NAT1 O N AL O R G AN I ZATl O N FO R STAN DAR D I ZAT I O N
IS0 RECOMMENDATION
R 300
PART I
IS0 IDENTIFICATION CODE FOR ROLLING BEARINGS
GROUP I - RADIAL BALL AND ROLLER BEARINGS
GROUP II - THRUST BALL AND ROLLER BEARINGS
GROUP III - TAPERED ROLLER BEARINGS, METRIC SERIES
1st EDITION
April 1963
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of EO.
For each individual country the only valid standard is the national standard of that country.
F’rinted in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
---------------------- Page: 1 ----------------------
BRIEF HISTORY
The IS0 Recommendation R 300 / Part I, IS0 Identification Code for Rolling Bearings:
Group I - Radial ball and roller bearings - Group II - Thrust ball and roller bearings -
Group III - Tapered roller bearings, metric series, was drawn up by Technical Committee
ISO/TC 4, Ball and Roller Bearings, the Secretariat of which is held by the Sveriges Stan-
dardiseringskommission (SIS).
Work on this question by the Technical Committee began in 1953 and led, in 1959, to the
adoption of a Draft IS0 Recommendation.
In October 1959, this Draft IS0 Recommendation (No. 157) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature,
by the following Member Bodies :
Australia Greece Romania
Austria Hungary Spain
Burma India Sweden
Canada Italy Switzerland
United Kingdom
Chile Japan
Netherlands U.S.A.
Czechoslovakia
Finland New Zealand U.S.S.R.
France Poland Yugoslavia
Germany Portugal
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Coun-
cil, which decided, in April 1963, to accept it as an IS0 RECOMMENDATION.
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CONTENTS
Page
Introduction .
4
Purpose of the Code .
4
Scope of the Code .
4
Structure of the Code .
4
Application of the Code .
6
1 . GROUP I: RADIAL BALL AND ROLLER BEARINGS .
9
1.1 Section 1: Basic Number .
10
1.1.1 Bore .
10
1.1.2 Type .
10
1.1.3 Outside diameter and width . 10
1.1.4 Bearing type symbols
A . Ball bearings .
11
B . Roller bearings .
13
1.2 Section 2: Modification of design .
16
A . Ball bearings .
16
B . Roller bearings .
16
1.2.1 Cage and separators .
16
1.2.2 Shields and seals
A . Ball bearings .
17
1.2.3 Duplex mounting modification
A . Ball bearings .
19
1.2.4 Bearing ring modification .
20
1.2.4.1 Snap ring groove
A . Ball bearings .
20
B . Roller bearings .
21
I .2. 4.2 Tapered bore
A . Ballbearings .
21
B . Roller bearings .
22
1.2.4.3 Miscellaneous modifications
A . Ball bearings .
22
B . Roller bearings .
22
1.3 Section 3: Internal fit and tolerances .
23
1.4 Section 4: Lubricants and preservatives .
24
1.5 Section 5: Special requirements .
26
2 . GROUP II: THRUST BALL AND ROLLER BEARINGS .
27
2.1 Section 1: Basic Number .
28
2.1.1 Bore .
28
2.1.2 Type .
28
2.1.3 Outside diameter and height .
28
2.1.4 Thrust bearing type symbols
A . Thrust ball bearings .
29
B . Thrust roller bearings . 29
2.2 Section 2: Modification of design .
30
2.2.1 Cage and separators .
30
2.2.2 Additional modifications . 31
2.3 Section 3: Tolerances .
32
2.4 Section 4: Lubricants and preservatives . 33
2.5 Section 5: Special requirements .
34
3 . GROUP III : TAPERED ROLLER BEARINGS, METRIC SERIES
............. 35
3.1
Section I: Basic Number . 36
3.1.1 Bore .
36
3.1.2 Type .
36
3.1.3 Outside diameter and width .
36
3.1.4 Bearing type symbols .
36
3.2 Section 2: Modification of design . 37
3.2.1 Cage .
37
3.2.2 Bearing ring modification .
38
3.2.2.1 Tapered bore .
38
3.2.2.2 Miscellaneous modifications .
38
3.3 Section 3: Internal fit and tolerances .
39
3.4 Section 4: Lubricants and preservatives . 40
3.5 Section 5: Special requirements .
41
APPENDIX 1 . - Special requirements : Specification items .
42
APPENDIX 2 . - IS0 Identification Code for Adapter and Withdrawal Sleeves . 44
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ISO/R 300/Part I - 1963 (E)
IS0 Recommendation R 300/Part I April 1963
IS0 IDENTIFICATION CODE FOR ROLLING BEARINGS
GROUP I - RADIAL BALL AND ROLLER BEARINGS
GROUP II - THRUST BALL AND ROLLER BEARINGS
GROUP III - TAPERED ROLLER BEARINGS, METRIC SERIES
INTRODUCTION
Purpose of the Code
The IS0 Identification Code for Rolling Bearings has been developed to identify and, as
far as possible, describe each bearing, on the basis of complete dimensional and functional
interchangeability.
The Code provides a universal language for describing and identifying bearings for the purpose
of facilitating communications between the user and the manufacturer. The Code is also meant
to simplify the handling by the user’s personnel of identical bearings, made by different manufac-
turers and identified by different numbers, whose meaning may be difficult to interpret, since the
various designation systems used by the several manufacturers are not identical, and generally
differ from this Code.
The Code is not meant to give any intimation whatsoever of the availability of different bearing
executions. For such purpose, the bearing manufacturers’ catalogues should be consulted.
Scope of the Code
The IS0 Identification Code applies only to those ball and roller bearings whose boundary
dimensions and tolerances are in agreement with the IS0 Recommendations.
---.
The Code makes no provisions for the numbering or identification of component parts of separ-
able type bearings or internal construction details, as no such details are the subject of IS0
Recommendations.
Tapered mounting sleeves are not identified by this IS0 Rolling Bearing Identification Code,
but have been covered by the IS0 Identification Code for Adapter and Withdrawal Sleeves (see
Appendix 2, page 44). The sleeve code number does not form part of the bearing code number.
IS0 Rolling Bearing Identification Code, including the
All amendments or expansions of the
Appendices, are allowed only if accepted by ISO.
Structure of the Code
The structure of the Code is a system of alternating groups of figures and letters.
The Code identifies the type and size of a ball or roller bearing by means of one group of figures
indicating the bearing bore diameter, followed by one group of letters, indicating the bearing
basic type, and one more group of figures, indicating the outside diameter and the width (or
height) of the bearing. The code number thus obtained is called the Basic Number and should
always be shown.
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ISOIR 300/Part I - 1963 (E)
Specific bearing characteristics conditioned by installation requirements may be identified by a
Supplementary Number consisting of alternating groups of letters and figures. Each such group
is called a Section. The indicators in each section vary in number according to the complexity of
information conveyed by each; also, each section of letters or figures deals only with one specific
subject, and hence, should always be considered as a unit.
As the alphabetical and numerical sections alternate, it is evident that in addition to conveying
specific information each intermediate section also serves as a separator to keep otherwise similar
sections apart. If an intermediate section is not used, it therefore should be replaced by a letter or a
figure to serve as a separator. The letter X and the figure O are used for this purpose.
TABLE 1. - Schematic arrangement of a complete code number
Section 2 i Section 3 Section 4 Section 5
Section 1
~~~ ~~~ ~~ ~~ ~ ~~
Basic Number Supplementary Number
l
,
Outside
Internal Lubricants Special
Modification ~
diameter
Bore 1 Type
fit and
and width of design and requirements
(or height)
1- ~~ ~~
O000 AAA O0
In the above Table, the figure O represents any Code figure, and the letter A any Code letter.
The symbols O and A in Table 1 therefore indicate whether figures or letters are used in the dif-
ferent sections, and also the number of Code symbols in each section.
It has not been deemed advisable to number all the complex products of the bearing industry
in an exactly uniform manner. The basic principle is uniform, but the practical structure of the
numbers varies somewhat according to the general class of bearing. The Code is therefore divided
into three groups :
Group I
Group II and
Group III
GROUP I comprises those ball bearings, cylindrical roller bearings and self-aligning roller bearings
whose space between raceways is oriented mainly parallel to the axis of rotation, and which are
primarily intended to carry radial or combined radial and thrust loads, pure thrust loads being
only incidental. Group I bearings are therefore referred to as radial bearings.
GROUP II comprises all those bail and roller bearings whose space between raceways is oriented
mainly perpendicular to the axis of rotation, and which are primarily intended to carry thrust
loads. They are referred to as thrust bearings.
GROUP III comprises tapered roller bearings, Metric Series.
The different groups are identified by the first type Code letter as shown in the following Table:
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~
lSO/R 3W/Part I - 1963 (E)
TABLE 2. - Designation of general type of bearing
First letter
Group Class of bearing
of type symbol
I I
B Radial ball bearings
I R Cylindrical roller bearings
S Self-aligning roller bearings
T Thrust ball and roller bearings
III K Tapered roller bearings, Metric Series
Application of the Code
it is necessary that the requirements as set forth in the Code be exactly followed. A thorough
study of the complete Code and the construction and content of each section should therefore
precede any endeavour to apply or interpret the Code.
Inasmuch as ball and roller bearings of different makes are not standardized in internal details
of construction, the Code should be applied with caution, in order to avoid the use of identical
numbers for bearings of a given type and size, but of different internal design or with different
properties which may materially affect the functional interchangeability. Conversely, there are
many cases in which bearings with different numbers may be dimensionally and functionally
interchangeable.
Table 3 (page 7) contains references to the pages in the Code on which the applicable sym-
bols are to be found.
Boundary dimensions and tolerance values may be found in the relevant IS0 Recommendations
(see list of references, page 8).
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lSO/R 300/Part I - 1963 (E)
ul e>
.-
t
ct:
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ISOIR 300/Part I - 1963 (E)
LIST OF REFERENCES RELATING TO BALL AND ROLLER BEARINGS
BOUNDARY DIMENSIONS OF RADIAL BEARINGS
1. IS0 Recommendation R 15, Ball and Roller Bearings:
Section 1, “General Plan for boundary dimensions of radial bearings (except tapered roller bearings)”;
Section 4, “Bearings with locating snap ring”;
Section 5, “General Pian for boundary dimensions of single-direction thrust bearings with flat seat”.
2. IS0 Recommendation R 104, Ball and Roller Bearings-Boundary Dimensions:
Section 1, “Radial bearings (except tapered roller bearings)-Intermediate boundary dimensions”;
Section 2, “Double-direction thrust bearings with flat seats - Boundary dimensions”.
3. IS0 Recommendation under preparation on Tapered Roller Bearings-Metric Series-Boundary Dimensions,
at present Draft IS0 Recommendation No. 154:
Section 2, “Boundary dimensions”;
Section 3, “Intermediate boundary dimensions”.
4. IS0 Recommendation under preparation on Radial Bearings-General Plan for Boundary Dimensions of Radial
Bearings (Except Tapered Roller Bearings) (revision of IS0 Recommendation R 15, section 1),
at present Draft IS0 Recommendation No. 358, under preparation.
5. IS0 Recommendation under preparation on Bearings with Locating Snap Ring (revision of IS0 Recommenda-
tion R 15, section 4), at present Draft IS0 Recommendation No. 360.
6. IS0 Recommendation under preparation on Single-Direction Thrust Bearings-General Plan for Boundary
Dimensions of Single-Direction Thrust Bearings with Flat Seat (revision of IS0 Recommendation
R 15, section 5), at present Draft IS0 Recommendation No. 361, under preparation.
7. IS0 Recommendation under preparation on Tapered Roller Bearings-Metric Series-Extension, at present
Draft IS0 Recommendation No. 472, under preparation.
BOUNDARY DIMENSIONS OF ACCESSORIES
8. IS0 Recommendation R 113, Ball and Roller Bearings-Accessories:
Section 1, “Tapered mounting sleeves : Boundary dimensions”.
NORMAL TOLERANCES
9. IS0 Recommendation R 15, Ball and Roller Bearings:
Section 2, “Normal tolerances for radial bearings (except tapered roller bearings)”;
Section 3, “Normal tolerances for tapered bore of radial bearings Taper 1 :12”.
10. IS0 Recommendation R 199, Rolling Bearings-Thrust Ball Bearings with Flat Seats-Normal Tolerances.
11. IS0 Recommendation under preparation on Radial Bearings-Normal Tolerances (Except Tapered Roller
Bearings) (revision of IS0 Recommendation R 15, section 2), at present Draft IS0 Recommen-
dation No. 359.
12. IS0 Recommendation under preparation on Tapered Roller Bearings-Metric SeriesNormal Tolerances, at
present Draft IS0 Recommendation No. 41 5, under preparation.
TOLERANCE CLASSES 6, 5 AND 4
13. IS0 Recommendation under preparation on Radial Bearings-Tolerance Classes 6, 5 and 4, at present Draft
IS0 Recommendation No. 280.
INTERNAL CLEARANCE
14. IS0 Recommendation R 201, Rolling Bearings-Radial Internal Clearance in Unloaded Radial Groove Type Ball
Bearings with Cylindrical Bore- Values.
15. IS0 Recommendation under preparation on Self-Aligning Roller Bearings-Radial Internal Clearance, at pre-
sent Draft IS0 Recommendation No. 470, under preparation.
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ISOIR 300/Part I - 1963 (E)
Group I
1. GROUP I: RADIAL BALL AND ROLLER BEARINGS
A bearing number in Group I is divided into five sections, of which Section 1 constitutes the Basic
Number and should always be shown. Sections 2 to 5 constitute the Supplementary Number.
No symbol in Section 1 should be omitted.
When Sections 2 to 5 are not needed, no symbol is shown in any of these sections.
When one or more intermediate sections are not needed, the cage symbol or the letter X is used
for Section 2, the figure O for Section 3 and the letter X for Section 4, to space the other sections
apart. Unused sections that otherwise would end a number are not shown.
TABLE 4. - Schematic arrangement of Group I
Group I: Radial ball and roller bearings
Supplementary Number
Basic Number
~~~ ~
Section 3 Section 4 Section 5
Section 1 Section 2
Type and Modification of Internal fit
and tolerances
boundary dimensions design
I
Lubricants
Shields ~ Bearing
Special
Outside
and
and seals rings
Cage
require-
l dia- inter- To-
pre-
and
ments
~~ ~
~~ ~~ nal ~ ler-
servatives
separa-
fit I ances
tors
Duplex mounting
1 width
I
modification
~ I
A~AA~ A 010 A O00
O000 1 AAA ~ O0
Section 1 (Basic Number) comprises symbols indicating bearing type and main boundary dimen-
sions: bore, outside diameter and width, as shown on pages 10 to 15.
Section 2 (Modification of design) establishes suffix letters indicating cage type or its modification,
as weU as those relating to shields, seals, snap ring groove, tapered bore and other modifications
of regular design, as shown on pages 16 to 22.
Section 3 (Internal fit and tolerances) establishes suffix figures indicating data, as shown on page 23.
Section 4 (Lubricants and preservatives) establishes suffix letters to identify types of lubricants
and preservatives, as shown on pages 24 and 25.
Section 5 (Special requirements) establishes suffix figures for specification items, as shown on
page 26 and in Appendix 1.
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ISOlR 3OOlPart I - 1963 (E)
Group I, Section 1
1.1 Section 1: Basic Number
TABLE 5. - Schematic arrangement of Section 1
Section 1 : Basic Number
-
Bore I Type 1 Outside diameter and width
0000 1 AAA 1 O0
I
1.1.1 Bore
The bearing bore is identified by code figures expressing the bore diameter in millimetres,
in accordance with the IS0 “General Plan for Boundary Dimensions of Radial Bearings
(except Tapered Roller Bearings)”. *
1.1.2 Type
Radial bearing types are identified by two or three code letters, of which the first letter
indicates the general type of bearing, as shown in the list below:
Symbols showing general type of bearing
B Radial ball bearings
R Cylindrical roller bearings
S Self-aligning roller bearings
The bearing type symbols showing detailed specifications are listed in clause 1.1.4, pages
11 to 15.
1.1.3 Outside diameter and width
The above-mentioned IS0 General Plan for Boundary Dimensions * provides various
outside diameters for each bore and a number of width series for each diameter series.
A certain width series in a certain diameter series is called a dimension series, which is
identified by a two-digit dimension series number.
The outside diameter and the width of the bearing are therefore identified by the dimen-
sion series number.
* See list of references (page 8): No. 1, section 1.
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ISO/R 3OO/Part I - 1963 (E)
Group I, Section 1
1.1.4 Bearing type symbols
A. BALL BEARINGS
1. Ball bearings, single row, radial contact
-
Symbol Description
BC Non-filling slot assembly
____ ~~ _____ ~~~ ~
BL Filling slot assembly
~~ ~
~ ~~ ____ ~~~ ~ ~~
BH Non-separable counter-bore assembly
-~ ____ ~~ ~~ ~~ ~ ~
'% T
BM Separable assembly
2. Ball bearings, single row, angular contact *
Symbol Description
BN Non-separable
Nominal contact angle from above 10" to and including 22"
~
BNS Separable outer ring
Nominal contact angle from above 10" to and including 22"
~
BNT Separable inner ring
Nominal contact angle : from above 10" to and including 22"
~~ ~ ~~~ ~~~ ~ ~~~ ~
BA Non-separable
Nominal contact angle : from above 22" to and including 32"
~~ ~ ~~~
_____~ - -
Separable inner ring
Nominal contact angIe : from above 22" to and including 32"
BT Non-separable
Nominal contact angle : from above 32" to and including 45"
BY Two-piece outer ring
- - ~~~ ~
BZ
Two-piece inner ring
-
* A line through the ball contact points forms an acute angle with a perpendicular to the bearing axis of rotation.
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lSO/R 300/Part I - 1963 (E)
3. Ball bearings, single row, radiai contact, spherical outside surface
Symbol Description
1-3; I Non-filling slot assembly
~~ ~ ~ ~~ ~ ~ ~
Filling slot assembly
4. Ball bearings, double row, radial contact
Description
Filling slot assembly
~ ~~__.
~- ~ ~ ~-
~~ ~__~ -
Non-filling slot assembly
@
-~ ~~~ -~ ~~
-.
Non-separable
Two-piece outer ring
5. Ball bearings, double row, angular contact
Description
Filling slot assembly
Vertex of contact angles inside bearing
~~___
__~~- __ ~~~ ___~
___~ ~~
Filling slot assembly
Vertex of contact angles outside bearing
- ~__ -~ ~ -~~- ~~~
-- -
Non-filling slot assembly
Vertex of contact angles inside bearing
~~ ~~ ~ ~~
__ ~~ -
Non-filling slot assembly
Vertex of contact angles outside bearing
Non-separable
Vertex of contact angles inside bearing
Two-piece outer ring
Separable
Vertex of contact angles outside bearing
Two-piece inner ring
No cage
Vertex of contact angles inside bearing
Free-turning ring with separating balls
6. Bail bearings, double row, self-aligning
Symbol Description
of outer ring spherical
BS Raceway
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@I.
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ISOlR 3ûûlPart I - 1963 (E)
Group I, Section 1
B. ROLLER BEARINGS
1. Cyiinàrical roller bearings, single row, non-locating type
-
Description
Symbol
-
RU Inner ring without ribs
Double-ribbed outer ring
Inner ring separable
~~ _ ~_
_ ~~_ ~~ _~ ~ ~
RUP Inner ring without ribs
Double-ribbed outer ring with one loose rib
Both rings separable 63
____~~~ __ ___ ~~ __ ~ ~~ ~ ~~-
Inner ring without ribs
Double-ribbed outer ring
Inner ring separable
a
Spherical outside surface
~ ~ -~ ~ ~~ ~ ~ ~ -
~
Double-ribbed inner ring
Outer ring without ribs
Outer ring separable a
~ __ ~~ ~ ___~ - ~ ~
Double-ribbed inner ring
Outer ring without ribs
Outer ring separable
Spherical outside surface
Inner ring without ribs
RM
Rollers located by cage end rings or internal snap rings
recessed in outer ring
Inner ring separable
____
___~_______~_ __
RN'I Inner ring without ribs
Outer ring without ribs
Both rings separable
2. Cylindrical roller bearings, single row, one-direction-locating type
Symbol Description
RR Single-ribbed inner ring
Outer ring with two internal snap rings
Inner ring separable @
___ -~ ~ ~~~~ -~ ~-
RJ Single-ribbed inner ring
Double-ribbed outer ring
Inner ring separable
-__
RJP Single-ribbed inner ring
Double-ribbed outer ring with one loose rib
Both rings separable
RF Double-ribbed inner ring
Single-ribbed outer ring
Outer ring separable
~.
RS Single-ribbed inner ring
Outer ring with one rib and one internal snap ring
Inner ring separabIe
~-
___ ~~~ -
RAA
Single-ribbed inner ring
Single-ribbed outer ring
Both rings separable
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ISO/R 3ûû/Part I - 1963 (E)
Group I, Section 1
3. Cylindrical roller bearings, single row, two-direction-locating type
Description
Symbol
Double-ribbed inner ring
RK
Outer ring with two internal snap rings
Non-separable
~ ~~ --
RC Double-ribbed inner ring
Double-ribbed outer ring
Non-separable
~ ~~~~ -
~ ~
RG Inner ring, with one rib and one snap ring
Double-ribbed outer ring
Non-separable
-~ ~ ~~
RP Double-ribbed inner ring
Double-ribbed outer ring with one loose rib
Outer ring separable
- ~~
-~
RY Double-ribbed inner ring
Outer ring with one rib and one internal snap ring
Non-separable
~~ ~ ~
~ ~~~~ ~~
RCS Double-ribbed inner ring
Double-ribbed outer ring
N on-separable
Spherical outside surface
- ~~
~ ~~~
RT Double-ribbed inner ring with one loose rib
Double-ribbed outer ring
Inner ring separable
-
4. Cylindrical roller bearings, double row, non-locating type
-
Description
Symbol
RA Tnner ring without ribs
Three integral ribs on outer ring
Inner ring separable
~~~ ~ ~~~
RD Three integral ribs on inner ring
Outer ring without ribs
m
Outer ring separable
~ ~~ -~ ~~ -~
RE Inner ring without ribs
Outer ring without ribs, with two internal snap rings
Inner ring separable
5. Cylindrical roller bearings, double-row , two direction-locating type
Symbol
Three integral ribs on inner ring
Outer ring without ribs, with two internal snap rings
Non-separable
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ISO/R 300/Part I - 1963 (E)
Group I, Section 1
6. Cylindrical roller bearings, multi-row, non-locating type
Description
Symbol
Inner ring without rjbs
RV
Double-ribbed outer ring (loose ribs)
Both rings separable
7. Self-aligning roller bearings, single row
-
Symbol Description
-
SR Inner ring with ribs
Raceway of outer ring spherical
Radial contact
SA Raceway of outer ring spherical
Angular contact
~ ~~ ~ ~~
~~ ~~ ~ -
Raceway of inner ring spherical
SB
Angular contact
-
Self-aligning roller bearings, double row
8.
Symbol Description
-
Three integral ribs on inner ring
SD
Raceway of outer ring spherical
SE Raceway of outer ring spherical
Separate centre guide ring in outer ring
m
~__
Raceway of inner ring spherical
sw
sc Raceway of outer ring spherical
Rollers guided by separate axially floating guide ring on inner ring
EXAMPLE
50BC02
50 = 50 mm bore diameter
BC = Ball bearing, single row, radial contact, non-filling slot assembly
= Dimension series 02, in which a 50 mm bore bearing has 90 mm outside diameter
02
and 20mm width (see IS0 Recommendation R 15, Ball and Roller Bearings,
page 16)
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ISO/R 3OOlPart I - 1963 (E)
Group I, Section 2
1.2 Section 2: Modification of design
When required to supplement the Basic Number of a ball or roller bearing, Section 2 expres-
ses the data shown below by means of a letter code arranged
in four or more columns for ball bearings, see Table 6 below.
in two or more columns for roller bearings, see Table 7 below.
When this section is used, column 1 should always be shown. The unused column or columns,
which would otherwise end a number, are not shown. For ball bearings, the intermediate
unused columns should be represented by the letter X.
When this section is not needed, but Sections 3, 4 or 5 are required, a bearing manufacturer
should show the actual cage symbol, whereas a bearing user may replace the section by a
A. BALL BEARINGS
TABLE 6. - Schematic arrangement of Section 2
Section 2: Modification of design
~~ ~ ~~~ ~
Column 1 ~ Column 2 Column 3 Column 4
I
Bearing ring
Shields and seals
modification
Cage and
separators
A A
A
B. ROLLER BEARINGS
TABLE 7. - Schematic arrangement of Section 2
Section 2: Modification of design
I I
I Column 1 Column 2
l I
Cage and Bearing ring
separators modifications
A A
1.2.1 Cage and separators
The cage or separators symbol is placed in column 1.
When no Supplementary Number is shown, the bearing is provided with manufacturer’s
regular cage.
When a Supplementary Number is needed, a bearing manufacturer should show the
actual cage symbol, whereas a bearing user may specify X, if type of cage is not man-
datory.
When X is specified, any type of cage may be furnished, unless Section 5, “Special
requirements”, calls for a particular type or execution of the cage. In the latter case,
the letter X in column 1 of this section is used only as a spacer.
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ISOIR 3001Part I - 1963 (E)
Group I, Section 2
Cage and separator symbols
Symbol
Columns Description
X Cage, any type acceptable
Spacer when a bearing requires supplementary coding of special cage
specified in Section 5
A Cage, steel, sheet or strip form, ring centred
l
Cage, steel, sheet, strip or wire form, centred by rolling elements
F J~
Cage, steel, not in sheet, strip or wire form
YI Cage, non-ferrous metal, sheet or strip form, centred by rolling
elements
B Cage, non-ferrous metal, sheet or strip form, ring centred
K
Cage, bronze or brass, not in sheet, strip or wire form, ring centred
M
Cage, bronze or brass, not in sheet, strip or wire form, centred by
.
rolling elements
H or wire form, ring
...