Classification of bearings
Counting the first or the first and second numbers together from left to right
"6" means deep groove ball bearing (Class 0)
"4" means double row deep groove ball bearing (Class 0)
"2" or "1" indicates self-aligning ball bearing (basic model with 4 numbers) (Category 1)
"21", "22", "23" and "24" denote self-aligning roller bearings. (3)
"N" means cylindrical roller bearing (including short cylindrical roller and part of slender needle roller) (Class 2)
The inner ring of "NU" has no flange.
"NJ" inner ring single guard edge.
"NF" outer ring single fender.
The outer ring of "N" has no fender.
"NN" double row cylindrical roller, outer ring without retaining edge.
"NNU" double row cylindrical roller, inner ring without flange.
The length of the roller is at least 5 times the diameter size, called needle roller bearings (Class 4)
"NA" rotary needle roller bearing with outer ring
"NK" stamped housing needle roller bearings
"K" needle roller and cage assembly, no inner and outer ring.
"7" means Angular contact ball bearing (Class 6)
"3" means tapered roller bearing (metric system) (Class 7)
"51", "52" and "53" indicate centripetal thrust ball bearings (five numbers for basic models) (8 categories)
"81" means thrust short cylindrical roller bearing (Class 9)
"29" means thrust self-aligning roller bearing (Class 9)
National standard for bearing
Rolling bearings -- Dimensions and tolerances of stop grooves and stop rings on outer rings
Steel balls for rolling bearings
Gb-t 309-2000 Rolling bearing needle roller
Rolling bearings -- Cylindrical rollers
Rolling bearings GB-T 4662-2003 Rated static load
Rolling bearings GB-T 6391-2003 Rated dynamic load and rated life
Jb-t 3034-1993 Rolling bearing oil seal anti-rust packaging
Jb-t 3573-2004 Measuring method of radial Clearance of rolling bearings
Jb-t 6639-2004 Rolling bearing parts skeleton NBR sealing ring technical specifications
Jb-t 6641-2007 Residual magnetism of rolling bearings and its evaluation method
Jb-t 6642-2004 Rolling bearing parts roundness and corrugation error measurement and evaluation method
Jb-t 7048-2002 Engineering plastic cage for rolling bearing parts
Jb-t 7050-2005 Rolling bearings cleanliness evaluation method
Jb-t 7051-2006 Rolling bearing parts surface roughness measurement and evaluation method
Jb-t 7361-2007 Rolling bearing parts hardness test method
Jb-t 7752-2005 Rolling bearings - Technical specifications for sealed deep groove ball bearings
Jb-t 8196-1996 Rolling bearing Residual magnetism of rolling body and its evaluation method
Jb-t 8571-1997 Rolling bearings sealed deep groove ball bearings test specification for dustproof, grease leakage and temperature rise performance
Jb-t 8921-1999 Rules for inspection of rolling bearings and their parts
Jb-t 10336-2002 Supplementary technical requirements for rolling bearings and their parts
Jb-t 50013-2000 Rolling bearing life and reliability test code
Jb-t 50093-1997 Rolling bearing life and reliability test evaluation method
Front code
The front code R is placed directly before the bearing basic code, and the rest codes are separated from the basic code by small dots.
GS. -- Thrust cylindrical roller bearing ring. Example: GS. 81112.
K. -- combination of rolling body and cage. Example: thrust cylindrical roller and cage assembly K.81108
R -- Bearings without detachable inner or outer rings. Example: RNU207 -- NU207 bearing without inner ring.
WS -- Thrust cylindrical roller bearing ring. Example: the WS. 81112.
Post code
The postcode is placed after the base code. When there are multiple groups of rear codes, they should be arranged from left to right in the order of the rear codes listed in the bearing code table. Some postcodes are preceded by dots from the base code.
Postcode - Internal structure
A, B, C, D, E -- Internal structural changes
Example: Angular contact ball bearings 7205C, 7205E, 7205B, C -- 15 ° contact Angle,E -- 25 ° antenna, B -- 40 ° contact Angle.
Example: Cylindrical roller, self-aligning roller and thrust self-aligning roller bearings N309E, 21309E, 29412E -- enhanced design, bearing load capacity increased.
VH -- Full roller cylindrical roller bearing with self-locking roller (the diameter of the compound circle of the roller is different from the standard bearing of the same type).
Example: NJ2312VH.
Rear code - bearing dimensions and external structure
DA -- Separable double row angular contact ball bearings with double half inner rings. Example: 3306 da.
DZ -- roller bearing with cylindrical outer diameter. Example: ST017DZ.
K -- Tapered bore bearing, taper 1:12. Example: 2308 k.
K30- Tapered bore bearing, taper 1:30. Example: 24040 K30.
2LS -- Double row cylindrical roller bearings with double inner rings and dust cover on both sides. Example: NNF5026VC.2Ls.v -- Internal structure change, double inner rings, with dust cover on both sides, double row cylindrical roller bearing with full roller.
N -- bearing with stop groove on outer ring. Example: 6207 n.
NR -- Bearing with stop groove and stop ring on outer ring. Example: 6207 NR.
N2- - Four-point contact ball bearing with two stop grooves on the outer ring. Example: QJ315N2.
S -- bearing with oil grooves and three oil holes in the outer ring. Example: 23040 S. Self-aligning roller bearings with bearing outer diameter D ≥ 320mm are not marked with S.
X -- Dimensions in line with international standards. Example: 32036 x
Z•• -- Technical conditions for special structures. Starting at Z11 and going down. Example: Z15 -- Stainless steel bearing (W-N01.3541).
ZZ - Roller bearing retainer with two guide outer rings.
Rear code - sealed and dust-proof
RSR -- Bearing side with sealing ring. Example: 6207 RSR
.2RSR -- Bearing with sealing rings on both sides. Example: 6207.2 RSR.
ZR -- Bearing with dust cover on one side. Example: 6207 ZR
.2ZR bearing with dust cover on both sides. Example: 6207.2 ZR
ZRN -- Bearing with dust cover on one side and stop groove on the other outer ring. Example: 6207 ZRN.
2ZRN -- Bearing with dust cover on both sides, with stop groove on the outer ring. Example: 6207.2 ZRN.
Rear code - Cage and its materials
1. Physical cage
A or B is placed after the cage code, where A indicates that the cage is guided by the outer ring and B indicates that the cage is guided by the inner ring.
F -- Steel solid cage with rolling body guide.
FA -- Steel solid cage with outer ring guide.
FAS -- Steel solid cage, outer ring guide, with lubrication groove.
FB -- Steel solid cage with inner ring guide.
FBS -- Steel solid cage, inner ring guide, with lubrication groove.
FH -- Steel solid cage, carburized and hardened.
H, H1 -- Carburizing and quenching retainer.
FP -- Steel solid window cage.
FPA -- Steel solid window cage with outer ring guide.
FPB -- Steel solid window cage with inner ring guide.
FV, FV1 -- Steel solid hole cage, aged and tempered.
L -- Light metal solid cage guided by rolling body.
LA -- Light metal solid cage, outer ring guide.
LAS -- Light metal solid cage, outer ring guide, with lubrication groove.
LB - Light metal solid cage with inner ring guide.
LBS - Light metal solid cage, inner ring guide, with lubrication groove.
LP -- Light metal solid window cage.
LPA -- Light metal solid window cage with outer ring guide.
LPB -- Light metal solid window cage, inner ring guide (thrust roller bearing as shaft guide).
M, M1 -- Brass solid cage.
MA -- Solid brass cage with outer ring guide.
MAS -- Solid brass cage, outer ring guide, with lubrication groove.
MB -- Brass solid cage, inner ring guide (thrust self-aligning roller bearing as shaft guide).
MBS -- Solid brass cage, inner ring guide, with lubrication groove.
MP -- Brass solid straight pocket holder.
MPA -- Brass solid straight pocket also retainer, outer ring guide.
MPB -- Brass solid straight pocket holder with inner ring guide.
T -- Phenolic laminate tube solid cage, rolling body guide.
TA -- Phenolic laminate tube solid retainer, outer ring guide.
TB -- Phenolic laminate tube solid retainer, inner ring guide.
THB -- Phenolic laminate tube pocket cage with inner ring guide.
TP - Phenolic laminate tube straight pocket holder.
TPA - Phenolic laminate tube straight pocket holder, outer ring guide.
TPB - Phenolic laminate tube straight pocket holder, inner ring guide.
TN -- Engineering plastic mold injection cage, rolling body guide, with additional numbers to indicate different materials.
TNH -- Engineering plastic self-locking pocket cage.
TV -- Glass fiber reinforced polyamide solid retainer, steel ball guided.
TVH -- Glass fiber reinforced polyamide self-locking pocket solid reholder guided by steel balls.
TVP -- Glass fiber reinforced polyamide window solid retainer, steel ball guided.
TVP2 -- Glass fiber reinforced polyamide solid cage, roller guided.
TVPB -- Glass fiber reinforced polyamide solid retainer, inner ring guide (thrust roller bearing as shaft guide).
TVPB1 -- Glass fiber reinforced polyamide solid window cage, shaft guided (thrust roller bearings).
2, stamping cage
J -- Steel plate stamping cage.
JN -- Riveting cage for deep groove ball bearing.
Cage change
The number added after or inserted in the cage code indicates that the cage structure has been changed. These numbers are only used for transitional periods, for example NU 1008M 1.
Rear code - no cage bearing
V -- Fully loaded rolling bearing. Example: NU 207V.
VT -- Fully loaded rolling bearing with isolation ball or roller. Example: 51120 n.
Post code - Tolerance class
(Dimensional accuracy and rotation accuracy)
P0 -- Tolerance class in accordance with the international standard ISO level 0, code omitted, does not indicate.
P6 -- Tolerance grade in accordance with ISO level 6.
P6X -- Grade 6 tapered roller bearings with tolerance class in accordance with international standard ISO.
P5 -- Tolerance class in accordance with the international standard ISO level 5.
P4 -- Tolerance grade in accordance with international standard ISO level 4.
P2 -- Tolerance class in accordance with international standard ISO class 2 (excluding tapered roller bearings).
SP -- Dimensional accuracy is equivalent to class 5 and rotation accuracy is equivalent to class 4 (double row cylindrical roller bearings).
UP -- Dimensional accuracy is equivalent to grade 4, and rotational accuracy is higher than grade 4 (double row cylindrical roller bearings).
HG -- Dimensional accuracy equivalent to grade 4, rotation accuracy higher than grade 4, lower than grade 2 (spindle bearing).
Rear code - clearance
C1 -- Clearance in accordance with the standard 1 group, less than 2 groups.
C2 -- 2 groups of clearance in accordance with the standard, less than 0 group.
C0 -- Group 0 of clearance in accordance with the standard, code omitted, does not represent.
C3 -- 3 groups of clearance in accordance with the standard, greater than 0 group.
C4 -- Clearance in accordance with the standard of 4 groups, greater than 3 groups.
C5 -- Clearance in accordance with the standard of 5 groups, greater than 4 groups.
When tolerance class code and clearance code need to be expressed at the same time, the combination of tolerance class code (P0 is not indicated) and clearance group number (0 is not indicated) is taken.
Example: P63=P6+C3, indicating bearing tolerance grade P6, radial clearance 3 groups.
P52=P5+C2, indicating bearing tolerance grade P5, radial clearance 2 groups.
For non-standard clearance, where special radial and axial clearance are required, the limit values concerned shall be expressed as A number of μ m after the letter R (radial clearance) or A (axial clearance), separated by small dots.
Example: 6210.R10.20 -- 6210 bearings, radial clearance 10 μ m to 20 μ m.
Bearings A120.160 -- 6212, Axial clearance 120 μ m to 160 μ m
Rear code - bearings for testing noise
F3 -- Low noise bearing. It mainly refers to cylindrical roller bearings and deep groove ball bearings with inner diameter D > 60mm and above. Example: 6213. The F3.
G -- Low noise bearing. It mainly refers to deep groove ball bearings with inner diameter D ≤ 60mm. Example: 6207 G
Post code - heat treatment
S0 -- Bearing ring after high temperature tempering treatment, the working temperature can reach 150 ℃.
S1 -- The bearing ring is tempered at high temperature and the working temperature can reach 200 ℃.
S2 -- Bearing ring after high temperature tempering treatment, the working temperature can reach 250 ℃.
S3 -- Bearing rings are tempered with high temperature, and the working temperature can reach 300 ℃.
S4 -- Bearing rings are tempered at high temperature to work at 350 ℃.
Postcode -- Special technical condition
F•• -- Manufacturing technical conditions for serial numbering. Example: F80 -- bearing inner and outer diameter tolerances and radial clearance compression.
K•• -- Technical requirements for continuous numbering. Example K5 -- bearing tolerance compression of inner and outer diameters.
.ZB -- cylindrical roller with convex diameter greater than 80mm. Example: NU 364.zb.
ZB2 -- The crown at both ends of the needle roller is greater than the general technical requirements. Example: K18 × 26 × 20F.zB2.
ZW -- Double row needle roller and cage assembly. Example: K20 × 25 × 40FZW.
.700•• -- Technical conditions for serial numbers beginning with 700000.
Z52JN.790144 -- Bearings can be used for high temperature and low speed, after special heat treatment, steel plate stamping riveting cage, large clearance, phosphating treatment, grease injection, the service temperature can exceed 270 ℃.
KDA - the Split inner ring /; Split inner ring
K -- Tapered bore 1:12
K30 -- Tapered bore 1:30
N -- Circular in the outer ring for snap ring
S -- What about groove and bores in the outer ring
The "S" suffix has been completely removed in the new E1 series! Outer ring filling groove and oil hole are now standard.
W03B Stainless steel bearing
N2 two retaining troves for fixing the outer ring
Two stop grooves for stop outer rings
Rear code - pair bearings and machine tool spindle bearings
1) Pairs of bearings that meet K technical conditions, and the following special technical conditions are related to pairs of bearings:
K1 -- Two sets of deep groove ball bearings are mounted in pairs to withstand unidirectional axial loads.
K2 -- Two sets of deep groove ball bearings are mounted in pairs to withstand bidirectional axial loads.
K3 -- Two sets of deep groove ball shafts are installed back-to-back with no clearance (O-type installation).
K4 -- Two sets of deep groove ball bearings are installed face to face with no clearance (type X).
K6 -- Two sets of angular contact ball bearings are mounted in pairs to withstand unidirectional axial loads.
K7 -- Two sets of angular contact ball bearings are mounted back to back with no clearance (O-type mounting).
K8 -- Two sets of angular contact ball bearings are mounted face to face without clearance (TYPE X)
K9 -- Two sets of tapered roller bearings with compartments between inner and outer rings are mounted in pairs to withstand unidirectional axial loads.
K10 -- Two sets of tapered roller bearings with ring between inner and outer rings mounted back to back without clearance (TYPE O mounting)
K11 -- Two sets of tapered roller bearings with a ring between the outer rings are installed face to face without clearance (type X installation).
Bearings in pairs or groups need to be packaged together for delivery or marked as belonging to a pair. Different sets of bearings are not interchangeable. When installing bearings belonging to the same group, the installation should be carried out in accordance with marks and positioning lines. If pairs of bearings are configured according to a certain axial or radial clearance amount, their clearance shall be indicated after K technical condition according to article 1 (2) of Item (7).
For example, 31314A.k11.A100.140 represents two sets of 31314A single row tapered roller bearings, mounted face to face, with a certain distance between the outer rings, bearing assembly front axial clearance between 100 μ m and 140 μ m, after assembly clearance is zero.
General purpose pair bearing
Can be installed in any pair (series, face to face or back to back), after code UA, UO and UL.
UA -- Small axial clearance when bearings are mounted face to face or back to back.
UO -- No clearance when bearing is installed face to face or back to back.
.ul -- Slight pre-interference when bearings are installed face to face or back to back. For example, b7004C.tPA.p4.k5.ul
Represents angular contact ball bearing with contact Angle of 15O for spindle, phenolic laminates with straight pocket solid retainer, outer ring guide, bearing tolerance class 4, reduced inner and outer diameter tolerance, universal construction for pairing, bearing with slight pre-interference when mounted back-to-back or face to face.
Rear code - machine tool spindle bearing
KTPA.HG clamp with this pocket solid cage, guided by outer ring, accuracy grade HG. Tpa.hg.k5.UL Clamp cloth to this pocket solid cage, outer ring guide, accuracy grade HG, bearing outer diameter and inner diameter tolerance reduction, all-body structure mounted in pairs, bearing with slight interference when mounted face to face or back to back.
Tpa.p2.k5.UL Clamp cloth to meet this pocket solid cage, outer ring guide, accuracy grade HG, bearing outer diameter and inner diameter tolerance reduction, all-body structure mounted in pairs, bearing with slight interference when mounted face to face or back to back.
Tpa. P2 UL Clamp fabric with this pocket solid cage, outer ring guide, accuracy grade HG, bearing tolerance reduction of outer and inner diameters, full-body structure mounted in pairs, bearing with slight interference when mounted face to face or back to back.
Rear code - machine tool spindle bearing
Tpa.p2.k5.UL Clamp fabric solid cage with pocket holes, outer ring guide, accuracy class HG, universal construction for mounting in pairs, bearing with slight interference when mounted face to face or back to back.
C Coulact Angle/contact Angle 15C
D Coulact Angle/contact Angle 25C
P4S Toerance Class P4S
Post time: Mar-21-2022