SKF single-row cylindrical roller bearings open design, NJ 211 ECP 55x100x21

Types NU, NJ, and NUP
Single-row SKF cylindrical roller bearings of the basic design are manufactured in many different versions, distinguished by the arrangement of the flanges on the inner and outer rings. The most common designs are:
Design NU
Bearings of design NU have two fixed flanges on the outer ring and a flange-less inner ring. The bearings allow axial displacement between the shaft and housing in both directions.
Design NJ
Bearings of design NJ have two fixed flanges on the outer ring and a fixed flange on the inner ring. They can guide the shaft axially in one direction. Axial displacement of the shaft is only possible in one direction.
Design NUP
Bearings of design NUP have two fixed flanges on the outer ring as well as a fixed flange and a loose flange disc on the inner ring. The bearing secures the shaft axially in both directions and is thus suitable for fixed supports.
Main dimensions: DIN 5412-1:2000 / DIN 616:2000 / ISO 15:1998

Permissible misalignment:
Bearing series 2, 3: 4°
Bearing series 22, 23: 3°

Suffixes:
EC Optimized internal design, more and/or larger rollers as well as modified roller/flange contact
P Cage made of glass-fiber reinforced polyamide 66, roller-guided
J Window cage made of unhardened steel sheet, roller-guided
C3 Clearance greater than normal
C4 Clearance greater than C4.