EN logo ZKL Group

Bearing designation is created by numerical and letter symbols indicating the type, size and design of the bearing, see the scheme.

In the basic design the bearings are designated by a basic designation which consists of bearing type and size designation. The type designation is usually created by the symbol indicating the bearing design (see position 3 in the scheme) and the symbol for dimension series or diameter series (positions 4 and 5 in the scheme), e.g. bearing type 223, 302, NJ22, 511, 62, 12, etc. Bearing size designation is created by symbols for the nominal bore diameter d (see position 6 in the scheme).

Bearings with bore diameter d<10 mm:

Digit separated by a slash, or the last digit indicates directly the bore dimension in mm, e.g. 619/2, 624.

Bearings with bore diameter d = 10 to 17 mm :

double digit number  
 00 indicates bore d = 10 mm, e.g. 6200
 01 d = 12 mm, e.g. 51101
 02 d = 15 mm, e.g. 3202
 03 d = 17 mm, e.g. 6303
An exception to the designation are separable single row ball bearings - types E and BO, where the double digit number indicates directly the bore diameter in mm, e.g. E17.

Bearings with bore diameter d = 20 to 480 mm :

Bore diameter is a fivefold of the last double digit number, e.g. bearing 1320 has the bore diameter d = 20 x 5 = 100.
An exception create bearings with bore d = 22, 28, and 32 mm, where the double digit number separated by a slash indicates directly the bore diameter in mm, e.g. 320/32AX, further separable single row ball bearings - type E and single row cylindrical roller bearings - type NG, where the double digit number, or number indicates directly the bore diameter in mm, e.g. : E20, NG160 C4SO.

Bearings with bore diameter d > 500 mm:

The last three or four digit number separated by a slash indicates directly the bore diameter in mm, e.g. 230/530M, NU29/1060.

Bearings produced in different design than standard are designated by so called complete designation, see the scheme. It consists of the basic designation and prefixes and suffixes indicating the difference from the basic design.

Meaning of Prefixes and Suffixes

In compliance with complete designation a survey and meaning of used prefixes and suffixes is given in the following part. (Number in brackets at individual groups corresponds to the position number in the scheme). 

Prefixes
Material Different from Standard Bearing Steel (1)

C - ceramic balls, e.g. C B7006CTA
X - corrosion resisiting steel, e.g. X 623
T - case hardened steel, e.g. T 32240
 
Incomplete Bearing (2)

L - removable ring of separable bearing, e.g. L NU206, for thrust ball bearings without shaft washer, e.g. L 51215
R - separable bearing without removable ring, e.g. R NU206 or R N310
E - single shaft washer of thrust roller bearing, e.g. E 51314
W - single housing washer of thrust ball bearing, e.g. W 51411
K - cage with rolling elements, e.g. K NU320 

Suffixes

Difference of Internal Design (7)

A - single row angular contact ball bearing, contact α = 25°, e.g. B7205ATB P5

- single row tapered roller bearing with higher load rating and higher limiting speed, 
  e.g. 30206A
- thrust ball bearing with higher limiting speed, e.g. 51105A

AA - single row angular contact ball bearing with contact angle α  = 26°, e.g. B7210AATB P4

B - single row angular contact ball bearing with contact angle α  = 40°,
e.g. 7304B
- single row tapered roller bearing with contact angle α > 17° e.g. 32315B

BE - single row angular contact ball bearing with contact angle α  = 40°,
in new design e.g. 7310BETNG

C - Single row angular contact ball bearing with contact angleα  = 15°,
e.g. 7220CTB P4
- double row spherical roller bearing in new design, e.g. 22216C

CA - single row angular contact ball bearing with contact angle α  = 12°,
e.g. B7202CATB P5

CB - single row angular contact ball bearing with contact angle α  = 10°,
např. B7206CBTB P4

CC - double row spherical roller bearing in new design, e.g. 23996CCM

D - single row ball bearing - type 160 with higher load rating, e.g. 16004D
 

E - single row cylindrical roller bearing with higher load rating, e.g. NU209E
- double row spherical roller bearing with higher load rating, e.g. 22215E
- spherical roller thrust bearing with higher load rating, e.g. 29416EJ

Difference of Boundary Dimensions (8)

X - change of boundary dimensions, introduced by new international standards, 
e.g. 32028AX

Shields or Seals (9)

RS - seal on one side, e.g. 6304RS
2RS - seals on both sides, e.g. 6204-2RS
RSN - seal on one side and snap ring groove in outer ring opposite to seal side, e.g. 6306RSN
RSNB - seal on one side and snap ring groove in outer ring on the same side as seal, e.g. 6210RSNB
2RSN - seals on both sides and snap ring groove in outer ring, e.g. 6310 2RSN
RSR - seal on one side adhering to flat surface of inner ring, e.g. 624RSR
2RSR - seals on both sides adhering to flat surface of inner ring, e.g. 608 2RSR
Z - metal shield on one side, e.g. 6206Z
2Z - metal shields on both sides, e.g. 6304 2Z
ZN - metal shield on one side and snap ring groove in outer ring opposite to metal shield, e.g. 6208ZN
ZNB - metal shield on one side and snap ring groove in outer ring on the same side as shield, e.g. 6306ZNB
2ZN - metal shields on both sides and snap ring groove in outer ring, e.g. 6208 2ZN
ZR - metal shield on one side adhering to flat surface of iner ring, e.g. 608ZR
2ZR - metal shields on both sides adhering to flat surface of inner ring, e.g. 608 2ZR

Bearing Ring Design Variation (10)

K - tapered bore, taper 1:12, e.g. 1207K
K30 - tapered bore, taper 1:30, e.g. 24064K30M
N - snap ring groove in outer ring, e.g. 6308N
NR - snap ring groove in outer ring and inserted snap ring, e.g. 6310NR
NX - snap ring groove in outer ring whose boundary dimensions do not correspond to STN 02 4605, e.g. 6210NX
D - split inner ring, e.g. 3309D
W33 - groove and lubrication holes in bearing outer ring surface, e.g. 23148W33M
O - lubrication grooves in bearing outer ring, e.g. NU1014O

Cages (11)

Cage material for bearings in basic design is not usually indicated.
J - pressed steel cage, rolling element centred, e.g. 6034J
J2 - pressed steel cage, rolling element centred, new design for single row tapered roller bearings, e.g. 30206AJ2
Y - pressed brass cage, rolling elements centred, e.g. 6001Y
F - machined steel cage, rolling elements centred, e.g.6418F
L - machined light metal cage, rolling elemnents centred, e.g. NG180L C3S0
M - machined brass or bronze cage, rolling elements centred, e.g. NU330M
T - machined cage made of textite, rolling elements centred, e.g. 6005T P5
TN - machined cage made of polyamide or similar plastic, rolling elements centred,
 e.g. 6207TN
TNG - machined cage made of polyamide or similar plastic with glass fibres, rolling elements centred, e.g. 2305TNG

Cage design (introduced symbols are always used in connection with cage material symbols).

A - cage centred on outer ring, e.g. NU226MA
B - cage centred on inner ring, e.g. B7204CATBP5
P - machined window-type cage, e.g. NU1060MAP
H - one-piece open-type cage, e.g. 629TNH
S - cage with lubrication grooves, e.g. NJ418MAS
V - bearing without cage, full rolling element number, e.g. NU209V

Tolerance Class (12)

P0 - standard tolerance class (not indicated), e.g. 6204
P6 - higher tolerance class than standard, e.g. 6322 P6
P5 - higher tolerance class than P6, e.g. 6201 P5
P5A - in some parameters higher tolerance class than P5, e.g. 6006TB P5A
P4 - higher tolerance class than P5, e.g. B7204CBTB P4
P4A - in some parameters higher tolerance class than P4, e.g. B7205CATB P4A
P2 - higher tolerance class than P4, e.g. B7205CATB P2
P6E - higher tolerance class for rotating electric machines, e.g. 6204 P6E
P6X - higher tolerance class for single row tapered roller bearings, e.g. 30210A P6X
SP - higher tolerance class for cylindrical roller bearings with tapered bore,
e.g. NN3022K SPC2NA
UP - higher tolerance class than SP for cylindrical roller bearings with tapered bore, e.g. N1016 UPC1NA

Clearances (13)

C2 - clearance less than normal, e.g. 608 C2
  normal clearance (not indicated), e.g. 6204
C3 - clearance greater than normal, e.g. 6310 C3
C4 - clearance greater than C3, e.g. NU320M C4
C5 - clearance greater than C4, e.g. 22330M C5
NA - radial clearance for bearings with non-interchangable rings (always after radial clearance symbol), e.g. NU215 P63NA
R... - radial clearance in non-standardized range (range in µm), e.g. 6210A R10-20
A... - axial clearance in non-standardized range (range in µm), e.g. 3210 A20-30

Vibration Level (14)

C6 - reduced vibration level lower than normal (not indicated) e.g. 6304 C6
C06 - reduced vibration level lower than C6, e.g. 6205 C06
C66 - reduced vibration level lower than C06, e.g. 6205 C66
Concrete C06 and C66 values are determined after negotiaitions between customer and supplier.

Note: Bearings in tolerance class P5 and higher have vibration level C6.

Increased Operation Safety (15)

C7, C8, C9 - bearings with increased operation safety determined primarily for aircraft industry, e.g. 16008 C8

Symbol Combination (12-15)

Symbols for tolerance class, bearing internal clearances, vibration levels and increased operation safety are combined, when symbol C is omitted from the second and following special bearing characteristics, e.g.:
P6 + C3 = P63 e.g. 6211 P63
P6 + C8 = P68 e.g. 16002 P68
C3 + C6 = C36 e.g. 6303-2RS C36
P5 + C3 + C9 = P539 e.g. 6205MA P539
P6 + C2NA + C6 = P626NA e.g. NU1038 P626NA

Bearing Arrangement in Matched Set (16)

Designation of the arrangement in matched sets of two, three or four bearings consists of symbols indicating the bearing arrangement and symbols determining internal clearance, or preload of matched bearings. 

 Besides symbols shown in the table also U symbol is used and it indicates that respective bearings can be universally matched, e. g. B7003CTA P4UL.

Internal Clearance or Preload

Introduced symbols are always used in combination with matching symbols.
A - bearing matching with clearance, e.g. 7305OA
O - bearing matching without clearance, e.g. 7305 P6XO
L - bearing matching with light preload, e.g. B7205CATB P4UL
M - bearing matching with medium preload, e.g. B7204CATB P5XM
S - bearing matching with great preload, e.g. B7304AATB P4OS

Stabilization for Operation at Higher Temperature

Both rings have stabilized dimensions for operation at higher temperature
S0 for operating temperature up to 150 ° C
S1 up to 200 °C
S2 up to 250 °C
S3 up to 300 °C
S4 up to 350 °C
S5 up to 400 °C

Designation example - NG160LB C4S3.

Friction Moment (18)

JU - reduced friction moment, e.g. 619/2 JU
JUA - bearings with determined friction moment for starting up, e.g. 623 JUA
JUB - bearings with determined friction moment for running out, e.g. 623 JUB

Grease (19)

For designation of bearings with shields or seals on both sides, filled with grease different from the standard one, symbol combinations are used for designation. The first two symbols determine the operating temperature range and the third (a letter) the name or type of lubricant, according to producer’s prescription, or another symbol (a digit) determines the grease volume, which the sealed or shielded inner bearing’s space is filled with.

TL - grease for low operating temperatures from -60°C to +100°C, 
  designation example 6302 2RS TL
TM - grease for medium operating temperatures from -35°C to +140°C, 
  designation example 6204 2ZR TM
TH - grease for high operating temperatures from -30°C to +200°C, 
  designation example 6202 2Z TH
TW - grease for both low and high operating temperatures from -40°C to +150°C, 
  designation example 6310 2Z C4TW
  Note: Symbol TM need not be marked on bearings and packages.

Bearings acccording to Special Technical Terms

TPF - bearings produced according to special technical conditions agreed with the customer, e.g. bearing 6205MA P66 according to special technical conditions TPF 11142-71 is de-signated: 6205MA P66 TPF142
TPF 99 - double row spherical roller bearing for arrangements of railway vehicle axles, e.g. 23234 C3 TPF99
TPF204 - single row ball bearings for fitting in kiln car wheels, etc., e.g. 6308 TPF204
TPFK - bearings according to special technical conditions agreed with the customer, which have a great number of symbols indicating variations from the basic design.
In this case only the designation TPF..., is given, e.g. bearing NU1015, produced according to technical conditions TPFK 11137-70 is designated NU1015 TPFK137.

Bearings according to Special Drawing Documentation PLC
PLC A-BC-DE-F designation structure

PLC - symbol for special rolling bearing
A - design group
 0 - single row ball bearings
 1 - double row ball bearings
 2 - thrust ball bearings
 3 - not occupied
 4 - single row cylindrical roller, spherical roller and needle roller bearings
 5 - double and multi-row cylindrical roller, spherical roller and needle roller bearings
 6 - single, double and four-row tapered roller bearings
 7 - special double row bearings
 8 - assembly units and separate parts
 9 - thrust cylindrical roller, spherical roller, tapered roller and needle roller bearings
BC - dimensional group - two digit symbols
DE - series number in dimensional group - two digit symbols
F - variation of design - one digit symbol