NSK bearings

NSK bearing nomenclature, Formulation of NSK bearing
numbers

NSK bearing numbers are alphanumeric combinations that indicate the NSK bearing type, boundary dimensions,
dimensional and running accuracies, internal clearance, and other related specifications. NSK bearing nomenclature
consist of basic numbers and supplementary symbols. The boundary dimensions of commonly used NSK
bearings mostly conform to the organizational concept of ISO, and the NSK bearing numbers of these standard
bearings are specified by JIS B 1513 (Bearing numbers for rolling bearings). Due to a need for more detailed
classification, NSK uses auxiliary symbols other than those specified by JIS.

NSK bearing numbers nomenclature consist of a basic number and supplementary symbols. The basic NSK number
indicates the NSK bearing series (type) and the width and diameter series as shown in table below. NSK basic
numbers supplementary symbols, and the meanings of common numbers and symbols are listed in table below. the
contact angle symbols and other supplementary designations are also shown in table.

NSK bearing series symbols

Bearing type Bearing series Type symbols Dimension symbols
symbols Width symbols

Diameter symbols

single-row deep 68 6 (1) 8
9
groove ball 69 (1) 0
2
bearings 60 (1) 3

62 (0)

63 (0)

Single-row 79 7 (1) 9
angular contact 70 (1) 0
ball bearings 72 1 (0) 2
73 1 (0) 3
Self-aligning ball (1)
bearings 12 (1) (0) 2
13 NU (0) 3
Single-row 22 2 2
cylindrical roller 23 2 3
bearings
NU10 1 0
NU2 (0) 2
NU22 2 2
NU3 (0) 3
NU23 2 3
NU4 (0) 4

Double-row NJ2 NJ (0) 2
cylindrical roller NJ22 NUP 2 2
bearings NJ3 N (0) 3
Needle roller NJ23 NF 2 3
bearings NJ4 NNU (0) 4
NN
Tapered roller NUP2 NA (0) 2
bearings NUP22 3 2 2
NUP3 (0) 3
Spherical roller NUP23 2 2 3
bearings NUP4 (0) 4
5
Thrust ball N10 1 0
N2 (0) 2
N3 (0) 3
N4 (0) 4

NF2 (0) 2
NF3 3
NF4 4 4
3
NNU29 9
NN30 4 0
4
NA48 5 8
NA49 6 9
NA59 9
NA69 2 9
2
329 3 9
320 3 0
330 0 0
331 2 1
302 3 2
322 0 2
332 2 2
303 3
323 3 3
3
230 2 0
231 3 1
222 0 2
232 2 2
213 3
223 1 3

511 1

bearings with flat 512 2 1 2
seats 513 1 3
514 1 4
Spherical thrust 522 2 2
roller bearings 523 2 3
524 2 4

292 9 2
293 3
294 4

NSK bearing nomenclature

1, Contact angle symbol
Angular contact ball bearings
 A: Standard contact angle of 30°
 A5: Standard contact angle of 25°
 B: Standard contact angle of 40°
 CStandard contact angle of 15°

Tapered roller bearings
 Ommitted: contact angle less than 17°
 C: contact angle about 20°
 D: contact angle about 28°

2, Internal design symbol
 A: Internal design differs from standard one.
 J: Smaller diameter of outer ring raceway, contact angle, and outer ring width of tapered roller bearings
conform to ISO 355

For high capacity NSK bearings
 C, CA, CD, EA: spherical roller bearings
 E: cylindrical roller bearings
 E: spherical thrust roller bearings

3, Material symbol
 g: Case-hardened steel used in rings, rolling elements
 h: stainless steel used in rings, rolling elements

4, Cage symbol
 M: machined brass cage
 W: pressed steel cage
 T: synthetic resin cage
 V: without cage

5, External features
Seals, shields symbol
 Z, ZS: shield on one side only
 ZZ, ZZS: shields on both sides
 DU: contact rubber seal on one side only
 DDU: contact rubber seals on both sides
 B: Non-contact rubber seal on one side only
 DDU: Non-contact rubber seals on both sides

Symbol for design of rings
 K: tapered bore of inner ring (Taper 1:12)
 K30: tapered bore of inner ring (Taper 1:30)
 E: Notch or lubricating groove in ring
 E4: Lubrication groove in outside surface and holes in outer ring
 N: snap ring groove in outer ring
 NR: snap ring groove with snap ring in outer ring

6, Arrangement Symbol
 DB: back-to-back arrangement
 DF: face-to-face arrangement
 DT: tandem arrangement

7, internal clearance Symbol and preload symbol

for all radial bearings
 C1: clearance less than C2
 C2: clearance less than CN
 Omitted: CN clearance
 C3: clearance GREATER than CN
 C4: clearance GREATER than C3
 C5: clearance GREATER than C4

for Non-interchangeable cylindrical roller bearings
 CC1: clearance less than CC2
 CC2: clearance less than CC
 CC: Normal clearance
 CC3: clearance GREATER than CC
 CC4: clearance GREATER than CC3
 CC5: clearance GREATER than CC4

for Extra-small and NSK Miniature ball bearings
 MC1: clearance less than MC2
 MC2: clearance less than MC3
 MC3: Normal clearance
 MC4: clearance GREATER than MC3
 MC5: clearance GREATER than MC4
 MC6: clearance GREATER than MC5

CM: Clearance in NSK Deep groove ball bearings and Cylindrical roller bearings(CM or CT) for electric Motors.
Preload of angular contact ball bearings
 EL: extra light preload
 L: light preload
 M: medium preload
 H: heavy preload

8, Tolerance class symbol
 Omitted: ISO Normal
 P6: ISO class6
 P6X: ISO class6X
 P5: ISO class5
 P4: ISO class4
 P2: ISO class2

for ABMA tapered roller bearing
 Omitted: class 4
 PN2: class 2
 PN3: class 3
 PN0: class 0
 PN00: class 00

9, special specification symbol
Bearings treated for dimensional stabilication
 X26: working temperature lower than 150°C
 X28: working temperature lower than 200°C
 X29: working temperature lower than 250°C

spherical roller bearings
 s11: dimensional stabiliging treatment working temperature lower than 200°C

10, Spacer or sleeve symbol
 +K: Bearings with outer ring spacers
 +L: Bearings with inner ring spacers
 +KL: Bearings with both inner and outer ring spacers
 H: adapter designation
 AH: withdrawal sleeve designation

 HJ: thrust collar designation

11, Grease symbol
 AS2: shell alvania grease S2
 ENS: ENS grease
 NS7: ns hI-LUBE
 PS2: Multemp PS No. 2