KoyoNJ315C4Cylindrical Roller Bearing 75 x 160 x 37 mm, NJ Design, One-Direction Location, C4 Clearance

Product Description

What this part is

A Koyo NJ315C4 single-row cylindrical roller bearing — 75 mm bore, 160 mm outside diameter, 37 mm wide, in the NJ design with one integral rib on the inner ring and C4 internal clearance.

Decoding the designation

NJ — one integral rib on the inner ring, giving axial location in one direction
315 — ISO 03 dimension series, 75 mm bore
C4 — radial internal clearance greater than C3, one step looser again
No cage letter — pressed steel cage

What these specs mean in practice

The design suffix on a cylindrical roller decides axial function and is the most consequential part of the number. An NJ has a single rib on the inner ring, so the roller set can push the shaft against that rib in one direction and no further; an N or NU has no rib and locates nothing; an NUP has ribs both sides and locates both ways. C4 clearance goes a step beyond C3, and it is chosen where the inner ring takes a heavy interference fit or where the inner ring runs much hotter than the outer — both consume clearance, and running a bearing to zero clearance is what kills it. The trade for that headroom is a little less radial stiffness and slightly more noise cold. Line-contact rollers give this type far higher radial capacity than a ball bearing of the same envelope, at the cost of speed and of any tolerance for misalignment.

Published specifications

Bore: 75 mm
Outside diameter: 160 mm
Width: 37 mm
Rows: 1
Rolling element: cylindrical roller
Cage: pressed steel
Internal clearance: C4, greater than C3
Axial location: one direction (NJ, single integral inner-ring rib)
Closure: open
Separable: yes — the inner ring lifts out of the roller-and-outer assembly

Quantity and configuration

1 Pc. Complete bearing — outer ring, roller complement with cage, and the ribbed inner ring. Two pieces are in stock from the same lot.

Interchange guidance

The ISO base number NJ315 identifies the same envelope and rib arrangement across brands: SKF NJ 315 ECP/C4, FAG NJ315-E-TVP2-C4, NSK NJ315WC4 and NTN NJ315C4 are the same 75 × 160 × 37 mm size at the same clearance grade. An NU315 or N315 is non-locating and an NUP315 locates both directions — same envelope, different axial function, so those are related sizes rather than equivalents. An NJ315 at CN or C3 clearance is a different clearance grade of the same bearing.