NU217 bearing: complete specifications & equivalents
The NU217 is a ISO 15 radial bearing sized 85 x 150 x 28 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 | 85 mm |
| Outer diameter D | 150 mm |
| Width B | 28 mm |
| Seal / shield | open |
| Internal clearance | CN / C3 / C4 available |
| Tolerance class | P0 |
| Cage | steel |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 1714 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 NU217 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & NU200-series range
| Bore d | 3.346 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.102 in |
| ISO bore code | 17 |
| Radial section height (D−d)/2 | 32.5 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) | 14 of 17 |
| Bore above smallest NU200-series size | 65 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU217 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 NU217 are bore code 17 = 85 mm (code × 5 from 04 upward). The ISO 15 envelope is 150 mm outside diameter and 28 mm width — 3.346 × 5.906 × 1.102 in, with a 32.5 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
- large fan and paper machine rolls
- rolling mill roll necks and chocks
- large gear drives and reducer shafts
- cement and mining machinery drives
- crusher eccentric and drum shafts
Known failure patterns
- 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
- cage fatigue and fracture after sustained over-speed with marginal lubrication
- fretting corrosion on an interference inner-ring seat that creeps under a loose fit
- false brinelling indentations at the roller pitch when an idle bearing sits in machine vibration
Selection pitfalls — read before you substitute
- The large 85 mm-bore NU217 mounts with substantial force: heat the inner ring or use hydraulic equipment, support the 150 mm outer ring squarely, and plan lifting fixtures for the 28 mm-wide roller assembly — drifting it in cold brinells the line-contact raceways.
- The NU2 light series at 85 mm bore (150×28 mm) is the default gearbox cylindrical row; on the same bore an NU317 is larger with a much higher rating — do not replace a failed NU317 with an NU217 without re-rating L10 life.
- Check the shoulder geometry for NU217: a generous fillet on the 85 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 150 mm, 28 mm-wide housing bore.
- Large NU217 rings need real draw-up force: use a sleeve or hydraulic press against the inner ring face only, verify the 85 mm seat temperature before assembly, and never strike the roller cage — a dented cage window on the 28 mm-wide set locks the rollers at the first hot run.
- When reusing separable NU217 rings, keep the matched pair together and inspect both seats: a crept inner ring frets a polished groove into the 85 mm journal that a new bearing will repeat unless the shaft is repaired or reclaimed.
- Cylindrical rollers have no self-aligning capacity: line contact across the 28 mm-wide rollers means even a few tenths of a degree of misalignment edge-loads the 150 mm raceway; where shaft deflection is unavoidable, use a spherical roller or a self-aligning ball bearing instead.
- Keep the minimum load above the skid threshold (catalogue rule of thumb roughly 1–2% of the dynamic rating); an unloaded NU217 on an idler or in a cold-start gearbox develops roller smearing, so add a spring preload or downsize the bearing if the duty is mostly empty.
Frequently asked questions
What are the dimensions of an NU217 cylindrical roller bearing?
An NU217 single-row cylindrical roller bearing per ISO 15 has a 85 mm bore, 150 mm outer diameter and 28 mm width (3.346 × 5.906 × 1.102 in), a 32.5 mm radial section and roughly 1714 g geometry-based estimated mass; catalogue masses vary with cage and E design.
How does the NU217 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 17: 17 × 5 = 85 mm. The 150 mm OD and 28 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 NU217) 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 NU217 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 NU217E) is the reinforced design: larger/optimised rollers raise the basic load rating over the basic designation in the same 85×150×28 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.