NU214 bearing: complete specifications & equivalents
The NU214 is a ISO 15 radial bearing sized 70 x 125 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | Generic ISO interchange (unbranded) |
| Bore diameter d | 70 mm |
| Outer diameter D | 125 mm |
| Width B | 24 mm |
| Seal / shield | open |
| Internal clearance | CN / C3 / C4 available |
| Tolerance class | P0 |
| Cage | steel |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 1032 g |
| Standard | ISO 15 |
| Catalog version | iso15-crb-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for NU214 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & NU200-series range
| Bore d | 2.756 in |
|---|---|
| Outer diameter D | 4.921 in |
| Width B | 0.945 in |
| ISO bore code | 14 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in NU200-series | 20 mm |
| Largest outer diameter in NU200-series | 180 mm |
| Width range across NU200-series | 14–34 mm |
| Bore position in NU200-series (smallest first) | 11 of 17 |
| Bore above smallest NU200-series size | 50 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU214 model number is decoded
In the NU200-series (ISO 15 dimension series) the leading NU marks a single-row cylindrical roller: the outer ring has two integral shoulders and the inner ring none, so the inner-ring/roller assembly floats axially both ways and the bearing locates radially only; the last two digits of NU214 are bore code 14 = 70 mm (code × 5 from 04 upward). The ISO 15 envelope is 125 mm outside diameter and 24 mm width — 2.756 × 4.921 × 0.945 in, with a 27.5 mm radial section height. Straight cylindrical rollers give line contact for high radial capacity at low friction, with no self-alignment; catalogue practice for a rotating inner ring is a k5 shaft seat, H7 housing and C3 clearance. NJ adds one inner shoulder (one-direction location), NUP two shoulders (full location); E denotes a reinforced roller complement — verify against the actual load direction.
Typical equipment & failure modes
Common applications
- centrifugal pump and compressor shafts
- machine tool gearboxes and feed drives
- conveyor and hoist gearcase shafts
- wind turbine gearbox intermediate shafts
- industrial helical and planetary gearboxes
Known failure patterns
- inner-ring shoulder damage from cold mounting force transmitted through the roller set
- thermal seizure when an interference fit plus hot running removes all residual C3 clearance
- roller and raceway smearing when a lightly loaded NU row skids at start-up or below the minimum load
- edge loading and rib spalling from shaft-to-housing misalignment — cylindrical rollers run on line contact and cannot self-align
- roller-end and flange scoring when an NU bearing is forced to locate axially; only NJ/NUP designs carry thrust at the shoulders
Selection pitfalls — read before you substitute
- On this 70 mm-bore NU214, set C3 as the default for an interference inner-ring fit and recheck play after mounting; a row that turned freely on the bench can be fully clamped once the 70 mm shaft reaches operating temperature.
- The NU2 light series at 70 mm bore (125×24 mm) is the default gearbox cylindrical row; on the same bore an NU314 is larger with a much higher rating — do not replace a failed NU314 with an NU214 without re-rating L10 life.
- Check the shoulder geometry for NU214: a generous fillet on the 70 mm shaft looks strong but stops the inner ring seating home; use the catalogue corner-relief radius and a withdrawal groove so the outer ring presses flush in the 125 mm, 24 mm-wide housing bore.
- Large NU214 rings need real draw-up force: use a sleeve or hydraulic press against the inner ring face only, verify the 70 mm seat temperature before assembly, and never strike the roller cage — a dented cage window on the 24 mm-wide set locks the rollers at the first hot run.
- When reusing separable NU214 rings, keep the matched pair together and inspect both seats: a crept inner ring frets a polished groove into the 70 mm journal that a new bearing will repeat unless the shaft is repaired or reclaimed.
- The E suffix denotes a reinforced design with larger rollers and higher rating than the basic NU214; never pair a standard and an E row on the same shaft — unequal stiffness splits the load unevenly, and the two are not life-equivalent despite the same envelope.
- At high speed, oil lubrication or a low-friction cage beats a grease-packed stamped-cage NU214: line-contact rollers churn grease hard, so follow the catalogue speed factor (n × dm) and preload the oil jet for sizes above the 70 mm bore band rather than extrapolating ball-bearing practice.
Frequently asked questions
What are the dimensions of an NU214 cylindrical roller bearing?
An NU214 single-row cylindrical roller bearing per ISO 15 has a 70 mm bore, 125 mm outer diameter and 24 mm width (2.756 × 4.921 × 0.945 in), a 27.5 mm radial section and roughly 1032 g geometry-based estimated mass; catalogue masses vary with cage and E design.
How does the NU214 bore code work?
The letters give the ring/shoulder design (NU = axially free, NJ = one inner shoulder, NUP = two shoulders) and the last two digits are bore code 14: 14 × 5 = 70 mm. The 125 mm OD and 24 mm width come from the ISO 15 dimension series (NU200), which shares its boundary plan with the 6-series deep-groove envelopes.
What is the difference between NU, NJ, N and NUP designs?
NU (like the NU214) has a shoulderless inner ring and floats axially in both directions; NJ has one integral inner-ring shoulder and locates the shaft in one direction; N has two inner shoulders and a shoulderless outer ring (mirror of NU); NUP adds a second, loose shoulder so the inner ring locates in both directions. Select by the shaft locating scheme, not by load rating — the envelopes are identical.
Can an NU214 take axial load or misalignment?
No thrust in the NU design: any sustained axial force scores the roller ends and ring flanges, so locate the shaft with an NJ/NUP row, a paired angular-contact bearing or a deep-groove row elsewhere. Misalignment is likewise not tolerated — line contact between cylindrical rollers and raceways edges under even small angular errors; use a spherical roller bearing where shaft deflection or housing misalignment is expected.
What does the E suffix mean and which clearance should be ordered?
E (as in NU214E) is the reinforced design: larger/optimised rollers raise the basic load rating over the basic designation in the same 70×125×24 mm envelope. For clearance, C3 is the usual default with an interference fit on a rotating inner ring because fit and thermal growth reduce residual play; use CN mainly for loose floating outer-ring mounts and C4 for hot or vibratory duty.
Reviewed & verified by the MPN Base engineering desk against source catalog iso15-crb-geometry on 2026-09-24. Read our editorial & correction policy.