NU209-NTN bearing: complete specifications & equivalents
The NU209-NTN is a ISO 15 radial bearing sized 45 x 85 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 45 mm |
| Outer diameter D | 85 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 51 kN |
| Basic static load rating C0 | 47 kN |
| Fatigue load limit Pu | 5.7 kN |
| Limiting speed (mechanical) | 8400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 423 g |
| Manufacturer designation | NTN NU209 |
| 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 & NU200-series range
| Bore d | 1.772 in |
|---|---|
| Outer diameter D | 3.346 in |
| Width B | 0.748 in |
| ISO bore code | 09 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in NU200-series | 15 mm |
| Largest outer diameter in NU200-series | 580 mm |
| Width range across NU200-series | 11–92 mm |
| Bore position in NU200-series (smallest first) | 8 of 36 |
| Bore above smallest NU200-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU209 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 45×85×19 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 NU209-NTN model number is decoded
NU209 is the standard section of the NTN NU200 dimension series for a 45 mm shaft — 51 kN of basic dynamic capacity in a 423 g, open bearing. Numbering ties NU209 to its envelope: type code NU, series NU200, 45 mm bore; the 85×19 mm outline therefore swaps dimensionally with other ISO 15 bearings of the same code, though rib arrangements differ by prefix. The 20.0 mm radial section ((85−45)/2) frames the roller complement; capacity per millimetre of bore is about 1.1 kN/mm before application factors. The 45 mm (1.772 in) bore and 85 mm (3.346 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 19 mm-wide ring. On NU arrangements confirm which ring is separable before heating: forcing the ribbed ring off over the roller complement damages the cage and rib faces.
Typical equipment & failure modes
Common applications
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
- machine-tool gearbox and spindle radial sets
- material-handling drum and wheel shafts
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage wear accelerated when the EA high-capacity roller complement runs continuously above its thermal balance
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- hard-particle indentation of raceways in unfiltered oil or open arrangements
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- On this 45 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NU209.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 85 mm race brinells and releases as vibration within hours.
- The NU rib arrangement is not interchangeable with another prefix on the same 45 mm seat: outer ring ribbed, inner ring ribless. Swapping NU for NJ changes axial location behaviour even though the 85×19 mm envelope matches.
- The 19 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 45 mm inner ring.
- The 20.0 mm section at 45 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 19 mm-wide cavity.
- The 51/47 kN ratings, 5.7 kN Pu and 423 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU209 (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 NU209?
NU209 is an NTN NU single-row cylindrical roller bearing to ISO 15: 45 mm bore, 85 mm OD and 19 mm width (1.772 × 3.346 × 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 51 kN, C0 47 kN, Pu 5.7 kN, grease limiting speed 8,400 r/min, oil 9,900 r/min, mass about 423 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. NU209 is two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially.
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. NU209 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can NU209 take axial load and locate a shaft?
the NU design carries no axial load and floats axially on both sides. Provide axial location with an adjacent locating bearing (angular-contact, deep-groove or a paired NJ/NUP set).
What do Fw and Ew mean for NU209?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 55 mm, Ew 75 mm. The nominal bore/OD remain 45/85 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 8,400 r/min grease / 9,900 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.