How to distinguish bearings by model number?
There are many types of bearings in contact with, and you will find that a lot of information is displayed in the bearing number. Through the model, we can directly know what kind of bearing it is, as well as its process and material. Next, I will divide the bearing model into three contents to explain, which are to distinguish the bearing classification through the model number, the meaning of the pre-code, and the meaning of the post-code.
A-Bearing classification
Counting from left to right the first or the first and second digits together
"6" means deep groove ball bearing
"4" means double-row deep groove ball bearings
"2" or "1" means self-aligning ball bearings (four numbers in total for the basic model)
"21", "22", "23" and "24" represent spherical roller bearings.
"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
"NA" Turning Cup Needle Roller Bearings
"NK" Stamped Case Needle Roller Bearings
"K" needle roller and cage assemblies, without inner and outer rings.
"7" means angular contact ball bearing
"3" indicates tapered roller bearings (metric system)
"51", "52" and "53" indicate radial thrust ball bearings (five numbers in total for the basic model)
"81" means thrust short cylindrical roller bearing
"29" means thrust spherical roller bearing
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B-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. the
WS—— Thrust cylindrical roller bearing shaft washer. Example: WS.81112.
C-Suffix code
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.
(A) 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. the
Example: Cylindrical roller bearing, spherical roller bearing and thrust spherical roller bearings N309E, 21309E, 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.
(B) suffix 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——
(C) Internal structure changes, 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.
(D)suffix code—Seal 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.
