Classification of bearings
Counting from left to right the first or the first and second digits together
"6" means deep groove ball bearing (0 category)
"4" means double row deep groove ball bearings (category 0)
"2" or "1" means self-aligning ball bearings (four numbers in total for the basic model) (category 1)
"21", "22", "23" and "24" represent spherical roller bearings. (3 categories)
"N" indicates cylindrical roller bearings (including short cylindrical rollers and part of slender needle rollers) (Class 2)
"NU" inner ring has no ribs.
"NJ" inner ring single rib.
"NF" outer ring single rib.
"N" outer ring has no ribs.
"NN" double row cylindrical roller, no rib on the outer ring.
"NNU" double row cylindrical rollers, inner ring without ribs.
The length of the roller is at least 5 times the diameter, which is called a needle roller bearing (category 4)
"NA" Turning Cup Needle Roller Bearings
"NK" turning needle roller bearing
"K" needle roller and cage assemblies, without inner and outer rings.
"7" means angular contact ball bearing (category 6)
"3" indicates tapered roller bearings (metric system) (category 7)
"51", "52" and "53" indicate radial thrust ball bearings (five numbers in total for the basic model) (8 categories)
"81" means thrust short cylindrical roller bearing (category 9)
"29" means thrust spherical roller bearing (category 9)
Bearing national standard
GB-T 305-1998 Dimensions and tolerances of snap grooves and snap rings on outer rings of rolling bearings
GB-T 308-2002 Rolling bearing steel balls
GB-T 309-2000 Rolling bearing needle roller
GB-T 4661-2002 rolling bearing cylindrical roller
GB-T 4662-2003 Rolling bearing rated static load
GB-T 6391-2003 Rolling bearing rated dynamic load and rated life
JB-T 3034-1993 rolling bearing oil seal antirust packaging
JB-T 3573-2004 Rolling bearing radial clearance measurement method
JB-T 6639-2004 Rolling bearing parts skeleton type nitrile rubber sealing ring technical conditions
JB-T 6641-2007 Rolling bearing residual magnetism and its evaluation method
JB-T 6642-2004 Rolling bearing parts, roundness and waviness error measurement and evaluation method
JB-T 7048-2002 rolling bearing parts engineering plastic cage
JB-T 7050-2005 Rolling Bearing 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 Bearing Sealed Deep Groove Ball Bearing Technical Conditions
JB-T 8196-1996 Rolling bearings Rolling element residual magnetism and its evaluation method
JB-T 8571-1997 Rolling bearings Sealed deep groove ball bearings Dustproof, grease leakage, temperature rise performance test procedures
JB-T 8921-1999 Inspection rules for rolling bearings and their parts
JB-T 10336-2002 Supplementary Technical Conditions for Rolling Bearings and Their Parts
JB-T 50013-2000 Rolling bearing life and reliability test procedures
JB-T 50093-1997 Rolling bearing life and reliability test evaluation method
Front code
The prefix code R is placed directly before the basic code of the bearing, and the other codes are separated from the basic code by small dots.
GS.——Thrust cylindrical roller bearing race. Example: GS.81112.
K.——Assembly of rolling element and cage. Example: Assemblies of thrust cylindrical rollers and cages K.81108
R——Bearings without separable inner or outer rings. Example: RNU207 - NU207 bearing without inner ring.
WS—— Thrust cylindrical roller bearing shaft washer. Example: WS.81112.
—— Interior design
—— Dimensions and deformation design
—— seal
—— Cage
—— Tolerance
—— Clearance
—— heat treatment
-- special design
—— Machine tool spindle bearing
—— Low noise and low bearing
postcode
The suffix code is placed behind the basic code. When there are multiple sets of suffix codes, they should be arranged from left to right in the order of the suffix codes listed in the bearing code table. Some suffix codes are separated from the basic code by a small dot.
Suffix code — internal structure
A, B, C, D, E - internal structure changes
Example: Angular contact ball bearings 7205C, 7205E, 7205B, C—15° contact angle, E—25° contact angle, B—40° contact angle.
Example: Cylindrical roller, spherical roller and thrust spherical roller bearings N309E, 21309 E, 29412E - reinforced design, bearing load capacity increased.
VH—— Roller self-locking full complement cylindrical roller bearing (the diameter of the complex circle of the roller is different from the standard bearing of the same type).
Example: NJ2312VH.
Subsequent code — Bearing dimensions and external structure
DA——Separable double row angular contact ball bearing with double half inner ring. Example: 3306DA.
DZ—— Cylindrical outer diameter roller bearing. Example: ST017DZ.
K—— Tapered bore bearing, taper 1:12. Example: 2308K.
K30- Tapered bore bearing, taper 1:30. Example: 24040 K30.
2LS—— Double row cylindrical roller bearing with double inner ring and dust cover on both sides. Example: NNF5026VC.2LS.V——internal structure change, double inner ring, with dust cover on both sides, full complement double row cylindrical roller bearing.
N——A bearing with a stop groove on the outer ring. Example: 6207N.
NR——A bearing with snap groove and snap ring on the outer ring. Example: 6207 NR.
N2———A four-point contact ball bearing with two stop grooves on the outer ring. Example: QJ315N2.
S——A bearing with lubricating oil grooves and three lubricating oil holes in the outer ring. Example: 23040S. Spherical roller bearings with bearing outer diameter D ≥ 320mm are not marked with S.
X—— Dimensions comply with international standards. Example: 32036X
Z••——Special structure technical conditions. Arranged in descending order from Z11. Example: Z15——stainless steel bearing (W-N01.3541).
ZZ—— roller bearing with two retaining rings that guide the outer ring.
Subsequent code — sealing and dustproof
RSR——The bearing has a sealing ring on one side. Example: 6207 RSR
.2RSR——The bearing has sealing rings on both sides. Example: 6207.2RSR.
ZR——The bearing has a dust cover on one side. Example: 6207 ZR
.2ZR bearings have shields on both sides. Example: 6207.2ZR
ZRN——The bearing has a dust cover on one side and a stop groove on the outer ring on the other side. Example: 6207 ZRN.
.2ZRN——The bearing has a dust cover on both sides and a stop groove on the outer ring. Example: 6207.2ZRN.
Subsequent code - cage and its material
solid cage
A or B is placed after the cage code, A means that the cage is guided by the outer ring, and B means that the cage is guided by the inner ring.
F——Steel solid cage, guided by rolling elements.
FA——Steel solid cage, guided by the outer ring.
FAS——Steel solid cage, outer ring guide, with lubrication groove.
FB——Steel solid cage, guided by the inner ring.
FBS——Steel solid cage, inner ring guide, with lubrication groove.
FH——Steel solid cage, carburized and quenched.
H, H1—— carburizing and quenching cage.
FP——steel solid window cage.
FPA——Steel solid window cage, guided by the outer ring.
FPB——Steel solid window cage, guided by the inner ring.
FV, FV1——Steel solid window cage, after aging, quenching and tempering treatment.
L——Light metal solid cage, guided by rolling elements.
LA——Light metal solid cage, guided by the outer ring.
LAS——Light metal solid cage, outer ring guide, with lubrication groove.
LB——Light metal solid cage, guided by the inner ring.
LBS——Light metal solid cage, inner ring guide, with lubrication groove.
LP——Light metal solid window cage.
LPA——Light metal solid window cage, guided by the outer ring.
LPB——Light metal solid window cage, inner ring guide (thrust roller bearing is shaft guide).
M, M1——Brass solid cage.
MA——Brass solid cage, guided by the outer ring.
MAS—Brass solid cage, outer ring guided, with lubrication groove.
MB——Brass solid cage, guided by the inner ring (thrust spherical roller bearings are guided by the shaft ring).
MBS—Brass solid cage, inner ring guided, with lubrication groove.
MP——Brass solid straight pocket cage.
MPA——Brass solid straight pockets and cages, outer ring guides.
MPB—Brass solid straight pocket cage, inner ring guided.
T—— Phenolic laminated cloth pipe solid cage, guided by rolling elements.
TA——Phenolic laminated cloth tube solid cage, guided by the outer ring.
TB——Phenolic laminated cloth tube solid cage, inner ring guide.
THB—— Phenolic laminated cloth tube pocket type cage, inner ring guide.
TP - phenolic layer grave cloth tube straight pocket cage.
TPA - phenolic laminated cloth tube straight pocket cage, outer ring guide.
TPB——Phenolic laminated cloth tube straight pocket cage, inner ring guide.
TN——engineering plastic injection molded cage, rolling body guide, with additional numbers to indicate different materials.
TNH——engineering plastic self-locking pocket cage.
TV——Glass fiber reinforced polyamide solid cage, guided by steel balls.
TVH—— Glass fiber reinforced polyamide self-locking pocket type solid cage, guided by steel balls.
TVP—glass fiber reinforced polyamide window-type solid cage, guided by steel balls.
TVP2 - glass fiber reinforced polyamide solid cage, roller guide.
TVPB - glass fiber reinforced polyamide solid cage, inner ring guide (thrust roller bearing is shaft guide).
TVPB1 - glass fiber reinforced polyamide solid window cage, shaft guided (thrust roller bearing).
Stamping cage
J —— steel stamping cage.
JN—— Deep groove ball bearing riveted cage.
Cage change
The number added after the cage code, or inserted in the middle of the cage code, indicates that the cage structure has been changed. These numbers are only used for transition periods, eg: NU1008M 1.
Subsequent code — bearing without cage
V —— Full complement rolling element bearing. Example: NU 207V.
VT——Full complement rolling element bearing with spacer balls or rollers. Example: 51120VT.
Subsequent code —— Tolerance class (dimensional accuracy and rotation accuracy)
P0—— Tolerance level conforms to level 0 stipulated by the international standard ISO, and is omitted in the code, not indicated.
P6—— Tolerance level conforms to level 6 stipulated by the international standard ISO.
P6X—— Tolerance class conforms to Class 6 tapered roller bearings stipulated by the international standard ISO.
P5—— Tolerance level conforms to level 5 stipulated by the international standard ISO.
P4—— Tolerance level conforms to level 4 stipulated by the international standard ISO.
P2—— Tolerance class conforms to Class 2 specified by the international standard ISO (excluding tapered roller bearings).
SP——Dimensional accuracy is equivalent to class 5, and rotational accuracy is equivalent to class 4 (double row cylindrical roller bearings).
UP——Dimensional accuracy is equivalent to class 4, and the rotational accuracy is higher than class 4 (double row cylindrical roller bearings).
HG—— Dimensional accuracy is equivalent to class 4, rotational accuracy is higher than class 4, and lower than class 2 (spindle bearings).
Suffix code — clearance
C1——The clearance conforms to Group 1 specified in the standard, and is less than Group 2.
C2—— Clearance conforms to group 2 specified in the standard, and is less than group 0.
C0—— Clearance conforms to group 0 stipulated in the standard, omitted in the code, not indicated.
C3—— Clearance conforms to Group 3 stipulated in the standard, and is greater than Group 0.
C4——The clearance conforms to the 4 groups stipulated in the standard, and is greater than 3 groups.
C5——The clearance conforms to the 5 groups stipulated in the standard, and is greater than 4 groups.
When the tolerance grade code and the clearance code need to be expressed at the same time, the combination of the tolerance grade code (not indicated for P0 level) and the clearance group number (not indicated for group 0) is used.
Example: P63=P6+C3, which means the tolerance class of the bearing is P6, and there are 3 groups of radial clearance.
P52=P5+C2, means bearing tolerance class P5, radial clearance 2 groups.
Non-standard clearance, in the case of special radial clearance and axial clearance, the relevant limit value should be expressed in μm after the letter R (radial clearance) or A (axial clearance), and the number Separate them with dots.
Example: 6210.R10.20 - 6210 bearings, radial clearance 10 μ m to 20 μ m.
6212.A120.160 - 6212 bearings, axial clearance 120μm to 160μm.
Subsequent code — bearings tested for noise
F3—— Low noise bearing. It mainly refers to cylindrical roller bearings and deep groove ball bearings with inner diameter d > 60mm or more. Example: 6213.F3.
G——Low noise bearing. Mainly refers to deep groove ball bearings with inner diameter d ≤ 60mm. Example: 6207.G
Suffix code — heat treatment
S0——The bearing ring has been tempered at high temperature, and the working temperature can reach 150 ℃.
S1——The bearing ring has been tempered at high temperature, and the working temperature can reach 200 ℃.
S2——The bearing ring has been tempered at high temperature, and the working temperature can reach 250 ℃.
S3——The bearing ring has been tempered at high temperature, and the working temperature can reach 300 ℃.
S4——The bearing ring is tempered at high temperature, and the working temperature can reach 350 ℃.
Suffix code — special technical conditions
F••——Continuously numbered manufacturing technical conditions. Example: F80—— bearing inner and outer diameter tolerance and radial clearance compression.
K••——Continuously numbered inspection technical conditions. Example K5——Bearing inner and outer diameter tolerance compression.
.ZB——Cylindrical rollers with crowns over 80mm in diameter. Example: NU 364.ZB.
.ZB2—— The convexity of 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•••——Continuously numbered specifications starting with 700000.
Z52JN.790144—— Bearing can be
Used for high temperature and low speed, after special heat treatment, steel stamping riveting cage, large clearance, phosphating treatment, grease injection, service temperature can exceed 270 ℃.
KDA——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——Lubricating groove and bores in the outer ring
The "S" suffix has been completely canceled in the new E1 series! Outer ring oil grooves and oil holes are now standard.
W03B Stainless steel bearing
N2 two retaining troves for fixing the outer ring
Two retaining grooves for retaining the outer ring
Subsequent designation — paired bearings and machine tool spindle bearings
1) Paired bearings complying with K technical conditions, the following special technical conditions are related to paired bearings:
K1—— Two sets of deep groove ball bearings are installed in pairs to bear one-way axial load.
K2—— Two sets of deep groove ball bearings are installed in pairs to bear bidirectional axial load.
K3—— Two sets of deep groove ball shafts are installed back to back without clearance (O type installation).
K4—— Two sets of deep groove ball bearings are installed face-to-face without clearance (X type installation).
K6—— Two sets of angular contact ball bearings are installed in pairs to bear one-way axial load.
K7—— Two sets of angular contact ball bearings are installed back to back without clearance (O type installation).
K8—— Two sets of angular contact ball bearings are installed face to face without clearance (X type installation)
K9——Two sets of tapered roller bearings with a spacer between the inner and outer rings are installed in pairs to bear unidirectional axial load.
K10——Two sets of tapered roller bearings with a spacer between the inner and outer rings are installed back-to-back without clearance (O-type installation)
K11——Two sets of tapered roller bearings with a spacer between the outer rings are installed face-to-face without clearance (X type installation).
Bearings configured in pairs or groups need to be packaged together for delivery, or marked as belonging to a pair. Bearings of different groups are not interchangeable. When installing bearings belonging to the same group, the installation should be carried out according to the marks and positioning lines. If each pair of bearings is configured according to a certain amount of axial or radial clearance, the clearance should be marked according to item 1 and 2) of item (7) after the K technical condition. For example, 31314A.K11.A100.140 means two sets of 31314A single row tapered roller bearings, installed face to face, with a certain distance spacer between the outer rings, the axial clearance of the bearings before assembly is between 100 μm and 140 μm, after assembly Play is zero.
Universal paired bearings
It can be paired and installed at will (tandem, face-to-face or back-to-back), and the rear codes are UA, UO and UL.
.UA——There is a small axial clearance when the bearings are installed face-to-face or back-to-back.
.UO - No backlash when bearings are mounted face-to-face or back-to-back.
.UL—Slight pre-interference when bearings are mounted face-to-face or back-to-back. For example, B 7004C .TPA.P4.K5.UL
Indicates angular contact ball bearings with a contact angle of 15o for the main shaft, phenolic laminated cloth tube straight pocket solid cage, outer ring guidance, bearing tolerance class 4, inner diameter and outer diameter tolerance reduction, general-purpose structure installed in pairs, Slight pre-interference when bearings are mounted back-to-back or face-to-face
Subsequent code — machine tool spindle bearing
KTPA.HG Pocket pocket solid cage, guided by the outer ring, precision grade HG. TPA.HG.K5.UL Pocket pocket solid cage, outer ring guide, precision grade HG, bearing outer diameter and inner diameter tolerance reduction, whole body structure installed in pairs, bearings are installed face-to-face or back-to-back with slight tolerance Interference.
TPA.P2.K5.UL Pocket pocket solid cage, outer ring guide, precision grade HG, bearing outer diameter and inner diameter tolerance reduction, whole body structure installed in pairs, bearings are installed face-to-face or back-to-back with slight tolerance Interference.
TPA.P2 UL is a solid cage with interlocking pockets, guided by the outer ring, precision grade HG, the tolerance of the outer diameter and inner diameter of the bearing is reduced, the whole structure is installed in pairs, and the bearings are installed face-to-face or back-to-back with a slight interference.
Subsequent code — machine tool spindle bearing
TPA.P2.K5.UL is a solid cage with interlocking pockets, guided by the outer ring, with an accuracy class of HG. It is a general structure installed in pairs. There is a slight interference when the bearings are installed face-to-face or back-to-back.
C coulact angle / contact angle 15C.
D coulact angle / contact angle 25C.
P4S toerance class P4S.
