Classification of bearings

Count from left to right, add the first or first and second numbers together

'6' represents deep groove ball bearings (Class 0)

'4' represents double row deep groove ball bearing (Class 0)

"2" or "1" indicates self-aligning ball bearings (four numbers in total for basic models) (Class 1)

21 ", 22", 23 ", and 24" represent self-aligning roller bearings. (Class 3)

'N' represents cylindrical roller bearings (including a portion of short cylindrical rollers and slender needle rollers) (Class 2)

The inner circle of 'NU' has no edges

NJ inner ring single edge

'NF' outer ring single edge

The outer ring of 'N' has no blocking edge

NN "double row cylindrical roller with no flange on the outer ring

NNU "double row cylindrical roller, inner ring without flange

A roller with a length at least 5 times the diameter size is called a needle roller bearing (Class 4)

"NA" Spinning Outer Ring Needle Roller Bearing

"NK" rotary needle roller bearing

K "needle roller and cage assembly, without inner and outer rings.

'7' represents angular contact ball bearings (Class 6)

'3' represents tapered roller bearings (metric) (Class 7)

'51', '52', and '53' represent radial thrust ball bearings (five numbers in total for basic models) (Class 8)

'81' represents thrust short cylindrical roller bearings (Class 9)

29 "represents thrust self-aligning roller bearings (Class 9)

National standard for bearings

Dimensions and tolerances of stop grooves and stop rings on the outer ring of rolling bearings (GB-T 305-1998)

GB-T 308-2002 Rolling Bearing Steel Balls

GB-T 309-2000 Rolling Bearing Needle Roller

GB-T 4661-2002 Rolling bearings - Cylindrical rollers

GB-T 4662-2003 Rated Static Load of Rolling Bearings

GB-T 6391-2003 Rolling bearings - Rated dynamic load and rated life

JB-T 3034-1993 Anti rust Packaging for Rolling Bearing Oil Seals

JB-T 3573-2004 Measurement Method for Radial Clearance of Rolling Bearings

JB-T 6639-2004 Technical conditions for skeleton nitrile rubber sealing rings for rolling bearing parts

JB-T 6641-2007 Residual Magnetism of Rolling Bearings and Its Evaluation Method

JB-T 6642-2004 Measurement and Evaluation Method for Roundness and Waviness Errors of Rolling Bearing Parts

JB-T 7048-2002 Rolling Bearing Parts Engineering Plastic Cage

JB-T 7050-2005 Evaluation Method for Cleanliness of Rolling Bearings

JB-T 7051-2006 Measurement and Evaluation Method for Surface Roughness of Rolling Bearing Parts

JB-T 7361-2007 Hardness Test Method for Rolling Bearing Parts

JB-T 7752-2005 Technical Conditions for Sealed Deep Groove Ball Bearings of Rolling Bearings

JB-T 8196-1996 Residual Magnetism of Rolling Bearings and Its Evaluation Method

JB-T 8571-1997 Rolling bearings - Sealing deep groove ball bearings - Dust prevention, grease leakage, and 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 Evaluation Method for Life and Reliability Testing of Rolling Bearings

Precode

The pre code R is placed directly before the basic code of the bearing, while the other codes are separated by small dots from the basic code

GS. - Thrust cylindrical roller bearing race. Example: GS.81112

K. - Combination of rolling element and cage. Example: Assembly K.81108 of thrust cylindrical roller and cage

R - Bearings without separable inner or outer rings. Example: RNU207- NU207 bearing without inner ring

WS - Thrust cylindrical roller bearing shaft ring. Example: WS.81112

——Internal design

——Outline dimensions and deformation design

——Sealing

——Holder

——Tolerance

——Clearance

——Heat treatment

——Special design

——Machine tool spindle bearings

——Low noise and energy-saving bearing

Post code

Place the post code after the base code. When there are multiple sets of 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 basic codes by small dots before them

Post code - internal structure

A. B, C, D, E - Changes in internal structure

Example: Angular contact ball bearings 7205C, 7205E, 7205B, C-15 ° contact angle, E-25 ° contact angle, B-40 ° contact angle

Example: Cylindrical roller, self-aligning roller, and thrust self-aligning roller bearings N309E, 21309E, 29412E - reinforced design, improved bearing load capacity

VH - Full cylindrical roller bearing with self-locking rollers (the complex diameter of the rollers is different from standard bearings of the same model)

Example: NJ2312VH

Post code - bearing dimensions and external structure

DA - Detachable double row angular contact ball bearing with double half inner ring. Example: 3306DA

DZ - Roller bearing with cylindrical outer diameter. Example: ST017DZ

K - Tapered hole bearing with a taper of 1:12. Example: 2308K

K30 tapered hole bearing with a taper of 1:30. Example: 24040 K30

2LS - Double row cylindrical roller bearing with dust cover on both sides of the double inner ring. Example: NNF5026VC.2LS.V - Internal structural change, double inner rings, dust covers on both sides, full roller double row cylindrical roller bearing

N - Bearings with stop grooves on the outer ring. Example: 6207N

NR - bearings with stop grooves and stop rings on the outer ring. Example: 6207 NR

N2- Four point contact ball bearing with two stop 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. Self-aligning roller bearings with outer diameter D ≥ 320mm are not marked with S

X - The overall dimensions comply with international standards. Example: 32036X

Z ••- Technical conditions for special structures. Starting from Z11, arrange it in descending order. Example: Z15- Stainless steel bearing (W-N01.3541)

ZZ - Retaining ring for roller bearing with two guide outer rings

Post code - Sealing and dustproof

RSR - One side of the bearing is equipped with a sealing ring. Example: 6207 RSR

. 2RSR - bearing with sealing rings on both sides. Example: 6207.2RSR

ZR - One side of the bearing is equipped with a dust cover. Example: 6207 ZR

The. 2ZR bearing is equipped with dust covers on both sides. Example: 6207.2ZR

ZRN - The bearing is equipped with a dust cover on one side and a stop groove on the outer ring on the other side. Example: 6207 ZRN

. 2ZRN - The bearing is equipped with dust covers on both sides and a stop groove on the outer ring. Example: 6207.2ZRN

Post code - Cage and its material

Solid holder

A or B are 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, guided by rolling element

FA - Steel Solid Cage, Outer Ring Guided

FAS - Steel solid cage with outer ring guide and lubrication groove

FB - Steel Solid Cage, Inner Ring Guided

FBS - Steel solid cage with inner ring guide and lubrication groove

FH - Steel solid cage, carburized and quenched

H. H1- Carburization quenching cage

FP - Steel solid window type holder

FPA - Steel solid window type holder with outer ring guide

FPB - Steel solid window type holder with inner ring guide

FV, FV1- Steel solid window hole holder, aged and tempered

L - Solid cage made of light metal, guided by rolling element

LA - Light metal solid cage with outer ring guide

LAS - Light metal solid cage with outer ring guide and lubrication groove

LB - Light metal solid cage with inner ring guide

LBS - Light metal solid cage with inner ring guide and lubrication groove

LP - Light metal solid window type holder

LPA - Light metal solid window type holder with outer ring guide

LPB - Light metal solid window type cage with inner ring guide (thrust roller bearing is shaft guided)

M. M1- Brass solid holder

MA - Brass Solid Cage, Outer Ring Guided

MAS - brass solid cage, outer ring guide, with lubrication groove

MB - Brass solid cage with inner ring guide (thrust self-aligning roller bearing with shaft ring guide)

MBS - brass solid cage, inner ring guide, with lubrication groove

MP - Brass solid straight pocket holder

MPA - Brass solid straight pocket with holder, outer ring guide

MPB - brass solid straight pocket holder with inner ring guide

T - Solid holder for phenolic laminated fabric pipe, guided by rolling element

TA - Solid holder for phenolic laminated fabric pipe, guided by outer ring

TB - Solid holder for phenolic laminated fabric pipe, guided by inner ring

THB - Phenolic laminated fabric pipe pocket holder with inner ring guide

TP - Phenolic layer burial cloth pipe straight pocket holder

TPA - Phenolic laminated fabric pipe straight pocket holder with outer ring guide

TPB - Phenolic laminated fabric pipe straight pocket holder with inner ring guide

TN - Engineering plastic injection cage, guided by rolling elements, with additional numbers representing different materials

TNH - Engineering plastic self-locking pocket hole type holder

TV - Glass fiber reinforced polyamide solid cage, guided by steel balls

TVH - Glass fiber reinforced polyamide self-locking pocket hole type solid cage, guided by steel balls

TVP - Glass fiber reinforced polyamide window solid cage, guided by steel balls

TVP2- Glass fiber reinforced polyamide solid cage, roller guided

TVPB - Glass fiber reinforced polyamide solid cage with inner ring guide (thrust roller bearing is shaft guided)

TVPB1- Glass fiber reinforced polyamide solid window cage, shaft guided (thrust roller bearing)

Stamped holder

J - Steel plate stamping cage

JN - Deep groove ball bearing riveted cage

Holder change

The number added after or inserted in the middle of the cage code indicates a change in the cage structure. These numbers are only used for transitional periods, such as NU1008M 1

Post code - bearing without cage

V - Fully loaded rolling element bearings. Example: NU 207V

VT - Fully loaded rolling element bearings with isolation balls or rollers. Example: 51120VT

Post code - tolerance level (dimensional and rotational accuracy)

P0- Tolerance level in accordance with the international standard ISO, level 0, omitted in the code, does not indicate

P6- Tolerance level in accordance with international standard ISO regulations, level 6

P6X - Grade 6 tapered roller bearings with tolerance levels in accordance with international standards ISO

P5- Tolerance level 5 in accordance with international standard ISO regulations

P4- Tolerance level in accordance with international standard ISO regulations, level 4

P2- Tolerance level 2 in accordance with international standard ISO (excluding tapered roller bearings)

SP - Dimensional accuracy equivalent to level 5, rotational accuracy equivalent to level 4 (double row cylindrical roller bearings)

UP - Dimensional accuracy is equivalent to level 4, and rotational accuracy is higher than level 4 (double row cylindrical roller bearings)

HG - Dimensional accuracy is equivalent to level 4, with rotational accuracy higher than level 4 and lower than level 2 (spindle bearing)

Post code - clearance

C1-1 group with clearance in accordance with standard regulations, less than 2 groups

C2-2 groups with clearance in accordance with standard regulations, less than 0 groups

C0- Group 0 with clearance in accordance with standard regulations, omitted from the code and does not indicate

C3-3 groups with clearance in accordance with standard regulations, greater than 0 groups

C4-4 groups with clearance in accordance with standard regulations, greater than 3 groups

C5-5 groups with clearance in accordance with standard regulations, greater than 4 groups

When the tolerance level code and clearance code need to be represented simultaneously, the combination of tolerance level code (P0 level not represented) and clearance group number (0 group not represented) is used to represent them

Example: P63=P6+C3, indicating bearing tolerance level P6, with 3 groups of radial clearance

P52=P5+C2, indicating bearing tolerance level P5, with 2 sets of radial clearance

Non standard clearance, where special radial and axial clearances are required, the limit values should be used after the letters R (radial clearance) or A (axial clearance) μ  The number m should be separated by small dots between the numbers

Example: 6210.R10.20-6210 bearing, radial clearance 10 μ M to 20 μ M

6212.A120.160-6212 bearing, axial clearance 120 μ M to 160 μ M

Post code - bearings for testing noise

F3- Low noise bearing. Mainly refers to cylindrical roller bearings and deep groove ball bearings with an inner diameter d>60mm or more. Example: 6213.F3

G - Low noise bearing. Mainly refers to deep groove ball bearings with an inner diameter d ≤ 60mm. Example: 6207. G

Post code - heat treatment

S0- The bearing ring has undergone high-temperature tempering treatment, and the working temperature can reach 150 ℃

S1- The bearing ring has undergone high-temperature tempering treatment, with a working temperature of up to 200 ℃

S2- The bearing ring has undergone high-temperature tempering treatment, and the working temperature can reach 250 ℃

S3- The bearing ring has undergone high-temperature tempering treatment, and the working temperature can reach 300 ℃

S4- The bearing ring has undergone high-temperature tempering treatment, and the working temperature can reach 350 ℃

Post code - special technical conditions

F ••- Manufacturing technical conditions with consecutive numbers. Example: F80- Bearing inner and outer diameter tolerances and radial clearance compression

K •• - Technical conditions for consecutive numbered inspections. Example K5- Bearing Inner and Outer Diameter Tolerance Compression

ZB - cylindrical rollers with protrusions and diameters greater than 80mm. Example: NU 364.ZB

ZB2- The convexity at both ends of the rolling needle is greater than the general technical requirements. Example: K18 ×  twenty-six ×  20F. ZB2

ZW - Double row needle roller and cage assembly. Example: K20 ×  twenty-five ×  40FZW

Technical conditions for consecutive numbers starting with 700000

Z52JN.790144- Bearings can be used at high temperatures and low speeds, undergo special heat treatment, steel plate stamping and riveting cages, have large clearance, undergo phosphating treatment, grease injection, and can be used at temperatures exceeding 270 ℃

KDA - Split inner ring/; Split inner ring

K - Tapered bore hole 1:12

K30 TAPERED BORE 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 removed in the new E1 series! The outer ring oil tank and oil hole have now become standard configurations

W03B Stainless steel bearing

N2 two retaining rocks for fixing the outer ring

Two stop grooves for stopping the outer ring

Post code - paired bearings and machine tool spindle bearings

1) Paired bearings that meet the K technical conditions are related to the following special technical conditions:

K1- Two sets of deep groove ball bearings installed in pairs to withstand unidirectional axial loads

K2- Two sets of deep groove ball bearings installed in pairs to withstand bidirectional axial loads

K3- Two sets of deep groove ball shafts installed back-to-back without clearance (O-ring installation)

K4- Two sets of deep groove ball bearings installed face to face without clearance (X-type installation)

K6- Two sets of angular contact ball bearings installed in pairs to withstand unidirectional axial loads

K7- Two sets of angular contact ball bearings installed back-to-back without clearance (O-ring installation)

K8- Two sets of angular contact ball bearings installed face to face without clearance (X-type installation)

K9- Two sets of tapered roller bearings with spacer rings between the inner and outer rings are installed in pairs to withstand unidirectional axial loads

K10- Two sets of tapered roller bearings with spacer rings between the inner and outer rings are installed back-to-back without clearance (O-ring installation)

K11- Two sets of tapered roller bearings with spacers between the outer rings are installed face to face without clearance (X-type installation)

Bearings configured in pairs or groups need to be packaged and delivered together, or marked as belonging to a pair. Bearings of different groups are not interchangeable. When installing bearings belonging to the same group, they should be installed according to the markings and positioning lines. If each paired bearing is configured with a certain axial or radial clearance, its clearance should be indicated after the K technical condition according to item 1 (2) in item (7). For example, 31314A. K11. A100.140 represents two sets of 31314A single row tapered roller bearings, installed face to face, with a certain distance between the outer rings, and an axial clearance of 100~140 before bearing assembly μ m. Zero clearance after assembly

Universal paired bearings

Can be installed in any pair (in series, face to face or back to back), with post codes UA, UO, and UL

UA - There is small axial clearance when installing bearings face to face or back to back

UO - No play when installing bearings face to face or back to back

UL - Mild pre interference when installing bearings face to face or back to back. For example, B 7004C. TPA. P4. K5. UL

Refers to the universal structure of angular contact ball bearings with a contact angle of 15o for the main shaft, phenolic laminated fabric pipe straight pocket solid cage, outer ring guide, bearing tolerance level 4, reduced inner and outer diameter tolerances, paired installation, with slight pre interference when installing the bearings back to back or face to face

Post code - machine tool spindle bearing

KTPA.HG Cloth Clamping, Pocket Hole Solid Cage, Outer Ring Guide, Accuracy Class HG. TPA.HG.K5.UL cloth clamp is a solid cage with a pocket hole, guided by the outer ring, with an accuracy level of HG. The tolerance of the outer diameter and inner diameter of the bearing is reduced, and the whole structure is installed in pairs. The bearing has slight interference when installed face to face or back to back.

TPA.P2.K5.UL cloth clamp with a solid cage, guided by the outer ring, with an accuracy level of HG. The bearing outer diameter and inner diameter tolerances are reduced, and the whole structure is installed in pairs. The bearing has slight interference when installed face to face or back to back.

TPA.P2 UL fabric clamp with a solid cage, outer ring guide, accuracy grade HG, reduced tolerance for outer diameter and inner diameter of bearings, paired installation of the entire structure, with slight interference when bearings are installed face to face or back to back

Post code - machine tool spindle bearing

TPA.P2.K5.UL Cloth Clamping Pocket Solid Cage, Outer Ring Guide, Accuracy Class HG, Universal Structure for Paired Installation, Mild Interference in Face to Face or Back to Back Installation of Bearings

C coordinate angle/contact angle 15C

D coordinate angle/contact angle 25C