ConsolidatedNU-315-M-C3Cylindrical Roller Bearing 75x160x37mm Non-Locating NU Design Brass Cage C3 Clearance

Product Description

What this part is

A single-row cylindrical roller bearing, 75 mm bore x 160 mm OD x 37 mm wide, in the NU non-locating design with a machined brass cage and C3 internal clearance. Cylindrical rollers carry far more radial load than a ball bearing of the same envelope because the rollers contact the raceways along a line rather than at a point. The 300 heavy series at this bore is built for gearboxes, electric motors, rolling mill and crusher shafts, and any position where radial load is the dominant problem.

Decoding the designation

NU — non-locating design: two integral ribs on the outer ring, a ribless inner ring, so the shaft is free to move axially within the bearing315 — ISO heavy series, 75 x 160 x 37 mmM — machined brass cageC3 — internal clearance greater than normal

What these specs mean in practice

The design suffix is the single most important thing on this bearing, and it is where substitutions go wrong. An NU bearing carries radial load only and provides no axial location at all — the rollers slide along the plain inner ring, which is exactly what you want at the non-locating end of a shaft so that thermal growth is absorbed instead of being pushed into the bearings. An NJ locates the shaft in one direction and an NUP in both. Substituting an NU where an NJ or NUP belongs lets the shaft walk, and the machine will tell you about it. C3 clearance runs looser than normal at rest, which suits hot running, tight interference fits and heavily loaded shafts where the inner ring grows relative to the outer. A machined brass cage takes higher speeds, shock loading and temperature than a pressed steel cage, and the cage code changes the load rating.

Published specifications

Bore: 75 mmOutside diameter: 160 mmWidth: 37 mmBearing type: single-row cylindrical rollerDesign: NU, non-locating (no axial location)Cage: machined brass (M)Internal clearance: C3, greater than normalSeries: 300, heavyRows: 1Closure: open

Quantity and configuration

One bearing. NU bearings have a separable inner ring, so the inner ring can be mounted on the shaft and the outer ring with rollers and cage into the housing, then brought together at assembly — a real advantage on a large shaft. Both parts belong to this bearing and are not interchangeable with the rings of another.

Fitting notes

Keep the inner and outer ring assemblies together as a matched unit; rollers are lapped to their own raceways. Heat the inner ring for mounting rather than pressing it cold onto a heavy interference fit, and never press through the rollers. Because this is a non-locating bearing, make sure the shaft is located somewhere else in the machine — and make sure the outer ring is free to allow the intended axial movement, not clamped by an over-tight end cap. Check that the roller set is square to the raceway before final assembly so no roller is skewed.

Interchange guidance

Direct equivalents are NU315 cylindrical roller bearings with a machined brass cage and C3 clearance from other makers — NU315-E-M1-C3 in the FAG scheme, NU315ECM/C3 in the SKF scheme, NU315EM C3 in the NSK scheme, and the ZKL NU315M C3 the carton references. Related but NOT interchangeable: NJ315 (locates one direction), NUP315 (locates both), N315 (ribs on the inner ring instead), and normal-clearance or polyamide/pressed-steel cage versions of the same number. Design suffix, clearance and cage all have to match.