Page 25 - NSK_CAT_E1102m_A7-141

BOUNDARY DIMENSIONS AND IDENTIFYING NUMBERS FOR BEARINGS

7.2 Formulation of Bearing Numbers (Example 4) NU 3 1 8 M CM Table 7. 5 Bearing Series Symbols

Bearing numbers are alphanumeric combinations Radial Clearance for Dimension Symbols Dimension Symbols
that indicate the bearing type, boundary dimensions, Electric-Motor Bearings CM
dimensional and running accuracies, internal clearance, Machined Brass Cage Bearing Type Bearing Type Bearing Type Bearing Type Width
and other related specifications. They consist of Bearing Bore 90mm Series Symbols Width Diameter Series Symbols
basic numbers and supplementary symbols. The Diameter Series 3 Symbols Symbols Symbols or Diameter
boundary dimensions of commonly used bearings NU Type Cylindrical Symbols Symbols
mostly conform to the organizational concept of ISO, Roller Bearing Height Symbols
and the bearing numbers of these standard bearings
are specified by JIS B 1513 (Bearing Numbers for (Example 5) NN 3 0 1 7 K CC1 P4 Symbols
Rolling Bearings). Due to a need for more detailed
classification, NSK uses auxiliary symbols other than Accuracy of ISO Class 4 Single-Row 68 6 (1) 8 Double-Row NNU49 NNU 4 9
those specified by JIS. Radial Clearance in Non- Deep Groove 69 6 (1) 9 Cylindrical NN30U NNU 3 0
Bearing numbers consist of a basic number and Interchangeable Cylindrical Ball Bearings 60 6 (1) 0 Roller Bearings
supplementary symbols. The basic number indicates Roller Bearings CC1 62 6 (0) 2 NA48 NA 4 8
the bearing series(type) and the width and diameter Tapered Bore (Taper 1:12) Single-Row 63 6 (0) 3 Needle Roller NA49 NA 4 9
series as shown in Table 7.5. Basic numbers, Bearing Bore 85mm Angular Contact Bearings NA59 NA 5 9
supplementary symbols, and the meanings of common Diameter Series 0 Ball Bearings 79 7 (1) 9 NA69 NA 6 9
numbers and symbols are listed in Table 7.6 (Pages Width Series 3 70 7 (1) 0
A56 and A57). The contact angle symbols and other NN Type Cylindrical Self-Aligning 72 7 (0) 2 Tapered Roller 329 3 2 9
supplementary designations are shown in successive Roller Bearing Ball Bearings 73 7 (0) 3 Bearings 320 3 2 0
columns from left to right in Table 7.6. For reference, (Example 6) HR 3 0 2 0 7 J 330 3 3 0
some examples of bearing designations are shown Single-Row 12 1 (0) 2 Spherical 331 3 3 1
here: Cylindrical 13 1 (0) 3 Roller 302 3 0 2
Roller 22 (1) 2 2 Bearings 322 3 2 2
(Example 1) 6 3 0 8 ZZ C3 Small Diameter of Cup Bearings 23 (1) 2 3 332 3 3 2
Radial Clearance C3 Raceway and Contact Angle Thrust Ball
(Internal Clearance Symbol) Conform to ISO NU10 NU 1 0 Bearings with 303 3 0 3
Bearing Bore 35mm NU20 NU (0) 2 Flat Seats 323 3 2 3
Shields on Both Sides Diameter Series 2 NU22 NU 2 2
(Shield Symbol) Width Series 0 230 2 3 0
Tapered Roller Bearing NU30 NU (0) 3 231 2 3 1
Bearing Bore 40mm High Capacity Bearing NU23 NU 2 3 222 2 2 2
(Bore Number) NU40 NU (0) 4
(Example 7) 2 4 0 /1000M K30 E4 C3 232 2 3 2
}Diameter Series 3 Bearing Radial Clearance C3 NJ20 NJ (0) 2 213 (1) 2 0 3
NJ22 NJ 2 2 223 2 2 3
Single-Row Deep Series
Groove Ball Bearing Symbol NJ30 NJ (0) 3 511 5 1 1
NJ23 NJ 2 3 512 5 1 2
(Example 2) 7 2 2 0 A DB C3 Outer Ring with Oil Groove NJ40 NJ (0) 4 513 5 1 3
and Oil Holes 514 5 1 4
Axial Clearance C3 Tapered Bore (Taper 1:30) NUP20 NUP (0) 2
Back-to-Back Arrangement NUP22 NUP 2 2 522 5 2 2
Contact Angle 30o Machined Brass Cage NUP30 NUP (0) 3 523 5 2 3
Bearing Bore 100mm Bearing Bore 1000mm 524 5 2 4
Diameter Series 2 Diameter Series 0 NUP23 NUP 2 3
Single-Row Angular Contact Ball Width Series 4 NUP40 NUP (0) 4 9 2
Bearing Spherical Roller Bearing 9 3
N10 N 1 0 9 4
(Example 3) 1 2 0 6 K +H206X N20 N (0) 2
N30 N (0) 3
Adapter with 25mm Bore (Example 8)5 1 2 1 5 N40 N (0) 4

Tapered Bore (Taper 1:12) Bearing Bore 75mm NF2 NF (0) 2 Spherical 292 2
Bearing Bore 30mm Diameter Series 2 NF3 NF (0) 3
Diameter Series 2 Height Series 1 NF4 NF (0) 4 Thrust Roller 293 2
Self-Aligning Ball Bearing Thrust Ball Bearing
Bearings 294 2

Note (1) Bearing Series Symbol 213 should logically be 203, but customarily it is numbered 213.
Remarks Numbers in ( ) in the column of width symbols are usually omitted from the bearing number.

A 54 A 55