NUP218 bearing: complete specifications & equivalents
The NUP218 is a ISO 15 radial bearing sized 90 x 160 x 30 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 90 mm |
| Outer diameter D | 160 mm |
| Width B | 30 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 169 kN |
| Basic static load rating C0 | 178 kN |
| Fatigue load limit Pu | 20.3 kN |
| Limiting speed (mechanical) | 4300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2250 g |
| Manufacturer designation | NTN NUP218 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & NUP200-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.181 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in NUP200-series | 17 mm |
| Largest outer diameter in NUP200-series | 580 mm |
| Width range across NUP200-series | 12–92 mm |
| Bore position in NUP200-series (smallest first) | 16 of 35 |
| Bore above smallest NUP200-series size | 73 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP218-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 90×160×30 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the NUP218 model number is decoded
NUP218 is an NTN NUP cylindrical roller bearing: the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions, inside the 90×160×30 mm ISO 15 envelope. Reading the code: NUP for the two-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 90 mm (00–03 use the 10/12/15/17 exception table). At 5,000 r/min with oil versus 4,300 r/min with grease (a 700 r/min band), lubrication choice for NUP218 is a thermal decision, not just a sealing one. Rating life at 169 kN C assumes clean oil and adequate film; the 20.3 kN Pu floor means contamination derating — not the C rating alone — governs adjusted life in dusty gearboxes. Heat the inner ring to max 120 °C for the 90 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.
Typical equipment & failure modes
Common applications
- marine gearbox and deck-machinery shafts
- large electric-motor and generator rotors
- cement and mining conveyor drive pulleys
- heavy industrial gearbox and reducer shafts
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- micro-pitting when the EHL film falls below the composite roughness at high specific load
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Induction-heat the 90 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 160 mm raceway.
- The 35.0 mm section at 90 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 30 mm-wide cavity.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 160 mm race brinells and releases as vibration within hours.
- Do not replace NUP218 with a deep-groove ball bearing on rating alone: line contact gives 169 kN radial capacity but the bearing only accepts small sustained axial guidance loads and misalignment tolerance is only 3–4 arc-minutes.
- Grease limiting speed 4,300 r/min and oil 5,000 r/min are different limits for NUP218: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- The 169/178 kN ratings, 20.3 kN Pu and 2250 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP218 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.
Frequently asked questions
What are the dimensions and catalogue data of NUP218?
NUP218 is an NTN NUP single-row cylindrical roller bearing to ISO 15: 90 mm bore, 160 mm OD and 30 mm width (3.543 × 6.299 × 1.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 169 kN, C0 178 kN, Pu 20.3 kN, grease limiting speed 4,300 r/min, oil 5,000 r/min, mass about 2250 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. NUP218 is the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NUP218 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NUP218 take axial load and locate a shaft?
the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NUP218?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 107 mm, Ew 143 mm. The nominal bore/OD remain 90/160 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 4,300 r/min grease / 5,000 r/min oil.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.