INA NA4906-2RS-C3 Nadellager (30x47x18)

As a needle roller bearing, this bearing carries high radial loads in a very compact section. This INA bearing measures 30x47x18 mm and weighs 0.104 kg; the specification table carries the supplementary technical details. This variant features increased radial clearance (C3). The needle roller bearing carries high radial load at the smallest section height of any rolling bearing type — slender rollers need little room above the shaft.

Needle rollers are long in relation to their diameter; they carry on a line while occupying very little radial space. Hence the defining property of this type: high radial capacity in the smallest section, paid for by being restricted to radial load — axial force is not carried and must be taken by an adjacent position. The solid design with its own rings differs from a needle cage or drawn cup in bringing its raceways with it, so it does not require hardened and ground running surfaces on shaft and housing.

Misalignment is critical: long rollers are sensitive to angular error because load then migrates to the roller ends, so seats must be aligned, accurate and stiff. The contact seal bears against its counterface and closes the rolling chamber against dust, splash water and wash-out; in return it raises frictional torque and limits permissible speed.

The slightly increased radial clearance provides reserve for tighter fits and for temperature differences between inner and outer ring, as they occur on shafts that run warm. Increased radial clearance C3 — Dimensional/form-fit equivalent — verify suffix-level details for critical applications. Matching suffixes are also listed by SKF (HC5C3, HC5C3WT, C3), FAG (C3), NSK (C3), NTN (C3) and NACHI (C3).