NU219 bearing: complete specifications & equivalents
The NU219 is a ISO 15 radial bearing sized 95 x 170 x 32 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 | 95 mm |
| Outer diameter D | 170 mm |
| Width B | 32 mm |
| Seal / shield | open |
| Internal clearance | CN / C3 / C4 available |
| Tolerance class | P0 |
| Cage | steel |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 2549 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 NU219 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & NU200-series range
| Bore d | 3.74 in |
|---|---|
| Outer diameter D | 6.693 in |
| Width B | 1.26 in |
| ISO bore code | 19 |
| Radial section height (D−d)/2 | 37.5 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) | 16 of 17 |
| Bore above smallest NU200-series size | 75 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the NU219 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 NU219 are bore code 19 = 95 mm (code × 5 from 04 upward). The ISO 15 envelope is 170 mm outside diameter and 32 mm width — 3.74 × 6.693 × 1.26 in, with a 37.5 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 gear drives and reducer shafts
- cement and mining machinery drives
- crusher eccentric and drum shafts
- heavy crane and winch drums
- large fan and paper machine rolls
Known failure patterns
- 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
- 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
Selection pitfalls — read before you substitute
- The large 95 mm-bore NU219 mounts with substantial force: heat the inner ring or use hydraulic equipment, support the 170 mm outer ring squarely, and plan lifting fixtures for the 32 mm-wide roller assembly — drifting it in cold brinells the line-contact raceways.
- The NU2 light series at 95 mm bore (170×32 mm) is the default gearbox cylindrical row; on the same bore an NU319 is larger with a much higher rating — do not replace a failed NU319 with an NU219 without re-rating L10 life.
- Before fitting NU219, machine the 95 mm shaft seat and 170 mm housing bore with a relief or undercut so nothing bridges the chamfer; the separable rings only carry load when their full faces abut, and a large fillet pinches the 37.5 mm radial section.
- With a separable NU219, mount the inner-ring/roller assembly on the shaft and the plain outer ring in the housing independently; check that the outer ring is free to float the specified amount after closing the housing — a pinched outer ring turns the floating bearing into an accidental locating one.
- Relubricate NU219 with the shaft turning so fresh grease or oil reaches the full 32 mm roller length; grease forced into a stationary row packs the entry and leaves the far side of the 95 mm bore starved.
- The rings of an NU219 are separable and supplied as a matched unit: never mix the outer ring of one bearing with the inner-ring/roller assembly of another — the raceway and roller complement are graded together, and cross-matching shortens life even at identical 95×170 dimensions.
- Apply mounting force to the ring with the interference fit — inner ring for a shaft fit, outer ring for a housing fit; pushing the 95 mm inner ring home through the rollers brinells the 170 mm outer raceway.
Frequently asked questions
What are the dimensions of an NU219 cylindrical roller bearing?
An NU219 single-row cylindrical roller bearing per ISO 15 has a 95 mm bore, 170 mm outer diameter and 32 mm width (3.74 × 6.693 × 1.26 in), a 37.5 mm radial section and roughly 2549 g geometry-based estimated mass; catalogue masses vary with cage and E design.
How does the NU219 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 19: 19 × 5 = 95 mm. The 170 mm OD and 32 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 NU219) 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 NU219 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 NU219E) is the reinforced design: larger/optimised rollers raise the basic load rating over the basic designation in the same 95×170×32 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.