21308CK Spherical Roller Bearings 40x90x23mm

21308CK   Spherical roller Bearings

Inner Diameter (ID):40    mm
Outer diameter (OD):90 mm

Width/Height: 23 mm    

Weight: 0.71  KG

Number of Row: Double row
Seals type: open
Characteristics: high speed

Material: No mark:Steel ball(SUJ2); SN24:Ceramic ball(Si3N4)
Cage structure:
TYN:polyamide resin cage
TR : Phenolic resin cage

BRASS:Brass cage
Combination of mark:
SU:Universal combination (single row)
DU:Universal combination (double rows)
DB: Back-to-back combination
DF: Face-to-face combination
DT: Parallel combination
DBD.DFD.DTD:  Three rows
DBB.DFF.DBT.DFT.DTT: Four rows
Preloaded mark: 
CAC: Large size bearings, roller is symmetrical
ECAC : Bearing roller and race surface by optimizing processing, helps to guide roller

CA : Roller is symmetrical, inner ring without guard.Each column roller with stamping steel cage
CC: Bearing roller and race surface by optimizing processing, help guide roller, and can reduce friction

E: Bearing load capacity is higher.E type bearing outer ring with a groove and three oil hole

Precision grade: 
P2 : ISO2;    
P4 : ISO4;  
P5 : ISO5
P3 : Special grade(Dimensional accuracy:ISO4,Rotation accuracy:ISO2)
p4Y: Special grade

Bearing clearance

C1-1 set of the clearance, clearance is less than 2 groups.
C2 - clearance conform to the standards stipulated by the two groups, group windage is less than 0.
C0 - clearance conform to the standards stipulated by the 0 group, code omitted, don\\\\\\\'t say.
C3 - clearance conform to the standards stipulated by the three groups, group clearance greater than 0.
C4 - clearance conform to the standards stipulated by the four groups, clearance is greater than three groups.
Of the C5 - clearance 5 groups, clearance is greater than the four groups.
When clearance code and tolerance grade bearing code P4, P5 or P6, saves clearance code C.