Classification of bearings
Count the first or the first and second numbers from left to right
"6" indicates deep groove ball bearing (Class 0)
"4" indicates double row deep groove ball bearing (Class 0)
"2" or "1" indicates self-aligning ball bearing (basic model has four numbers) (Class 1)
"21" "22" "23" "24" indicates spherical roller bearing. (Class 3)
"N" indicates cylindrical roller bearing (including short cylindrical roller and part of slender needle roller) (Class 2)
"NU" inner ring without flange.
"NJ" inner ring single flange.
"NF" outer ring single flange.
"N" outer ring without flange.
"NN" double row cylindrical roller, outer ring without flange.
"NNU" double row cylindrical roller, inner ring without flange.
The roller length is at least 5 times the diameter size, which is called a needle roller bearing (Class 4)
"NA" turned outer ring needle roller bearing
"NK" stamped shell needle roller bearing
"K" needle roller and cage assembly, without inner and outer rings.
"7" indicates angular contact ball bearings (Class 6)
"3" indicates tapered roller bearings (metric) (Class 7)
"51","52" and "53" indicate radial thrust ball bearings (basic model has five numbers) (Class 8)
"81" indicates thrust short cylindrical roller bearings (Class 9)
"29" indicates thrust spherical roller bearings (Class 9)
Prefix
The leading code R is placed directly before the basic code of the bearing, and the other codes are separated from the basic code by a dot.
GS.--Thrust cylindrical roller bearing race. Example: GS.81112.
K.--Assembly of rolling element and cage. Example: K.81108, assembly of thrust cylindrical roller and cage.
R--Bearing without separable inner or outer ring. Example: RNU207--NU207 bearing without inner ring.
WS--Thrust cylindrical roller bearing shaft ring. Example: WS.81112.
Code-Behind
The post-code is placed after the basic code. When there are multiple post-codes, they should be arranged from left to right in the order of the post-codes listed in the bearing code table. Some post-codes are separated from the basic code by a small dot.
Post-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, 21309E, 29412E - enhanced design, bearing load capacity is improved.
VH - roller self-locking full roller cylindrical roller bearing (the roller's compound circle diameter is different from the standard bearing of the same model).
Example: NJ2312VH.
Postcode - bearing dimensions and external structure
DA - separable double-row angular contact ball bearing with double semi-inner rings. Example: 3306DA.
DZ - roller bearing with cylindrical outer diameter. 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 rings and dust covers on both sides. Example: NNF5026VC.2LS.V - internal structure changes, double inner rings, dust covers on both sides, full-fill double-row cylindrical roller bearings.
N - bearing with retaining groove on the outer ring. Example: 6207N.
NR--Bearing with retaining groove and retaining ring on the outer ring. Example: 6207 NR.
N2---Four-point contact ball bearing with two retaining grooves on the outer ring. Example: QJ315N2.
S--Bearing with lubricating oil groove and three lubricating oil holes on the outer ring. Example: 23040 S. Spherical roller bearings with bearing outer diameter D≥ 320mm are not marked with S.
X--Outer dimensions meet the requirements of international standards. Example: 32036X.
Z••--Technical conditions for special structures. Arranged from Z11 downwards. Example: Z15--Stainless steel bearing (W-N01.3541).
ZZ--Roller bearing with two retaining rings to guide the outer ring.
Postcode - Sealing and Dustproof
RSR - bearing with a seal on one side. Example: 6207 RSR.
.2RSR - bearing with seals on both sides. Example: 6207.2RSR.
ZR - bearing with a dust cover on one side. Example: 6207 ZR.
.2ZR - bearing with dust covers on both sides. Example: 6207.2ZR.
ZRN - bearing with a dust cover on one side and a retaining groove on the outer ring on the other side. Example: 6207 ZRN.
.2ZRN - bearing with dust covers on both sides and a retaining groove on the outer ring. Example: 6207.2ZRN.
Postcode - cage and its material
1. Solid cage
A or B is placed after the cage code, A means the cage is guided by the outer ring, B means the cage is guided by the inner ring.
F--Steel solid cage, rolling element guided.
FA--Steel solid cage, outer ring guided.
FAS--Steel solid cage, outer ring guided, with lubrication groove.
FB--Steel solid cage, inner ring guided.
FBS--Steel solid cage, inner ring guided, with lubrication groove.
FH--Steel solid cage, carburized and quenched.
H, H1--Carburized and quenched cage.
FP--Steel solid window cage.
FPA--Steel solid window cage, outer ring guided.
FPPB--Steel solid window cage, inner ring guided.
FV, FV1--Steel solid window cage, aging and tempering.
L--Light metal solid cage, rolling element guided.
LA - Light metal solid cage, outer ring guide.
LAS - Light metal solid cage, outer ring guide, with lubrication groove.
LB - Light metal solid cage, inner ring guide.
LBS - Light metal solid cage, inner ring guide, with lubrication groove.
LP - Light metal solid window type cage.
LPA - Light metal solid window type cage, outer ring guide.
LPB - Light metal solid window type cage, inner ring guide (thrust roller bearing is shaft guide).
M, M1 - Brass solid cage.
MA - Brass solid cage, outer ring guide.
MAS - Brass solid cage, outer ring guide, with lubrication groove.
MB - Brass solid cage, inner ring guide (thrust spherical roller bearing is shaft guide).
MBS - Brass solid cage, inner ring guide, with lubrication groove.
MP - Brass solid straight pocket cage.
MPA--Brass solid straight pocket cage, outer ring guide.
MPB--Brass solid straight pocket hole cage, inner ring guide.
T--Phenolic laminated cloth tube solid cage, rolling element guide.
TA--Phenolic laminated cloth tube solid cage, outer ring guide.
TB--Phenolic laminated cloth tube solid cage, inner ring guide.
THB--Phenolic laminated cloth tube pocket hole cage, inner ring guide.
TP--Phenolic laminated cloth tube straight pocket hole cage.
TPA--Phenolic laminated cloth tube straight pocket hole cage, outer ring guide.
TPB--Phenolic laminated cloth tube straight pocket hole cage, inner ring guide.
TN--Engineering plastic injection molded cage, rolling element guide, with additional numbers to indicate different materials.
TNH--Engineering plastic self-locking pocket hole cage.
TV--Glass fiber reinforced polyamide solid cage, steel ball guide.
TVH--Glass fiber reinforced polyamide self-locking pocket hole type solid cage, steel ball guided.
TVP--Glass fiber reinforced polyamide window type solid cage, steel ball guided.
TVP2--Glass fiber reinforced polyamide solid cage, roller guided.
TVPB--Glass fiber reinforced polyamide solid cage, inner ring guided (thrust roller bearing is shaft guided).
TVPB1--Glass fiber reinforced polyamide solid window type cage, shaft guided (thrust roller bearing).
2. Stamped cage
J--Steel stamped 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 changed. These numbers are only used in transitional periods, for example: NU 1008M 1.
Post-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.
Suffix code - tolerance grade
P0--Tolerance grade conforms to Grade 0 specified in the international standard ISO, omitted in the code and not indicated.
P6--Tolerance grade conforms to Grade 6 specified in the international standard ISO.
P6X--Tolerance grade conforms to Grade 6 tapered roller bearing specified in the international standard ISO.
P5--Tolerance grade conforms to Grade 5 specified in the international standard ISO.
P4--Tolerance grade conforms to Grade 4 specified in the international standard ISO.
P2--Tolerance grade conforms to Grade 2 specified in the international standard ISO (excluding tapered roller bearings).
SP--Dimensional accuracy is equivalent to Grade 5, and rotational accuracy is equivalent to Grade 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 is equivalent to Grade 4, and rotational accuracy is higher than Grade 4, but lower than Grade 2 (spindle bearings).
Postcode -bearing clearance
C1--Clearance meets the requirements of the standard for group 1, less than group 2.
C2--Clearance meets the requirements of the standard for group 2, less than group 0.
C0--Clearance meets the requirements of the standard for group 0, omitted in the code and not indicated.
C3--Clearance meets the requirements of the standard for group 3, greater than group 0.
C4--Clearance meets the requirements of the standard for group 4, greater than group 3.
C5--Clearance meets the requirements of the standard for group 5, greater than group 4.
When the tolerance grade code and the clearance code need to be indicated at the same time, the tolerance grade code (P0 grade is not indicated) plus the clearance group number (0 group is not indicated) are combined to indicate.
Example: P63=P6+C3, indicating that the bearing tolerance grade is P6 and the radial clearance is 3 groups.
P52=P5+C2, indicating that the bearing tolerance grade is P5 and the radial clearance is 2 groups.
For non-standard clearance, when special radial clearance and axial clearance are required, the relevant limit values should be expressed in μm after the letter R (radial clearance) or A (axial clearance), and the numbers should be separated by dots.
Example: 6210.R10.20 - 6210 bearing, radial clearance 10μm to 20μm.
6212.A120.160 - 6212 bearing, axial clearance 120μm to 160μm.
Postcode - Bearings tested for noise
F3 - Low noise bearings. Mainly refers to cylindrical roller bearings and deep groove ball bearings with inner diameter d＞60mm or more. Example: 6213.F3.
G - Low noise bearings. Mainly refers to deep groove ball bearings with inner diameter d≤60mm. Example: 6207.G
Postcode - Heat Treatment
S0-- The bearing rings are subjected to high temperature tempering treatment, and the working temperature can reach 150 ℃.
S1-- The bearing rings are subjected to high temperature tempering treatment, and the working temperature can reach 200 ℃.
S2-- The bearing rings are subjected to high temperature tempering treatment, and the working temperature can reach 250 ℃.
S3-- The bearing rings are subjected to high temperature tempering treatment, and the working temperature can reach 300 ℃.
S4-- The bearing rings are subjected to high temperature tempering treatment, and the working temperature can reach 350 ℃.
Postcode-Special Technical Conditions
F••--Manufacturing technical conditions with consecutive numbers. Example: F80--Bearing inner and outer diameter tolerances and radial clearance compression.
K••--Inspection technical conditions with consecutive numbers. Example K5--Bearing inner and outer diameter tolerance compression.
.ZB--Cylindrical rollers with a diameter greater than 80mm with convexity. Example: NU 364.ZB.
.ZB2--The convexity 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 with consecutive numbers starting with 700000.
Z52JN.790144--Bearings can be used at high temperatures and low speeds, with special heat treatment, steel plate stamping and riveting cages, large clearance, phosphating treatment, grease injection, and the use 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 eliminated in the new E1 series! The outer ring oil groove and oil hole are now standard.
W03B Stainless steel bearing
N2 two retaining troves for fixing the outer ring
Two retaining grooves for fixing the outer ring
Postcode - Paired bearings and machine tool spindle bearings
1) For paired bearings that meet the 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 withstand unidirectional axial loads.
K2 - Two sets of deep groove ball bearings are installed in pairs to withstand bidirectional axial loads.
K3 - Two sets of deep groove ball bearings 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 withstand unidirectional axial loads.
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 spacers between the inner and outer rings are installed in pairs to withstand unidirectional axial loads.
K10--Two sets of tapered roller bearings with spacers between inner and outer rings are installed back to back without clearance (O-type installation)
K11--Two sets of tapered roller bearings with spacers between outer rings are installed face to face without clearance (X-type installation).
Bearings arranged in pairs or groups need to be packed together for delivery or marked as belonging to a pair. Bearings from 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 arranged according to a certain axial or radial clearance, its clearance should be indicated after the K technical conditions according to item 1, 2 in (7).
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 100μm and 140μm, and the clearance is zero after assembly.
Universal matching bearings
Can be matched and installed in any way (in series, face to face or back to back), with the suffix codes UA, UO and UL.
.UA - There is a small axial clearance when the bearings are mounted face to face or back to back.
.UO - There is no clearance when the bearings are mounted face to face or back to back.
.UL - There is a slight pre-interference when the bearings are mounted face to face or back to back. For example, B 7004C .TPA.P4.K5.UL.
Indicates an angular contact ball bearing with a contact angle of 15o for the spindle, a phenolic laminated cloth tube straight pocket solid cage, an outer ring guide, a bearing tolerance grade 4, a reduced inner diameter and outer diameter tolerance, a universal structure for pairing, and a slight pre-interference when the bearings are mounted back to back or face to face.
Post-code - machine tool spindle bearing
KTPA.HG cloth-stitched cross-hole solid cage, outer ring guide, precision grade HG. TPA.HG.K5.UL cloth-stitched cross-hole solid cage, outer ring guide, precision grade HG, bearing outer diameter and inner diameter tolerances are reduced, full-body structure installed in pairs, bearings are installed face to face or back to back with slight interference.
TPA.P2.K5.UL cloth-stitched cross-hole solid cage, outer ring guide, precision grade HG, bearing outer diameter and inner diameter tolerances are reduced, full-body structure installed in pairs, bearings are installed face to face or back to back with slight interference.
TPA.P2 UL cloth-stitched cross-hole solid cage, outer ring guide, precision grade HG, bearing outer diameter and inner diameter tolerances are reduced, full-body structure installed in pairs, bearings are installed face to face or back to back with slight interference.
Postcode - Machine tool spindle bearings
TPA.P2.K5.UL cloth-strap cross-hole solid cage, outer ring guide, precision grade HG, universal structure for installation in pairs, bearings have slight interference when installed face to face or back to back.
C coulact angle / contact angle 15C.
D coulact angle / contact angle 25C.
P4S toerance class P4S.
