N211 bearing: complete specifications & equivalents
The N211 is a ISO 15 radial bearing sized 55 x 100 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 100 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 64.5 kN |
| Basic static load rating C0 | 62.5 kN |
| Fatigue load limit Pu | 7.6 kN |
| Limiting speed (mechanical) | 6900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 626 g |
| Manufacturer designation | NTN N211 |
| 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 & N200-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.827 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in N200-series | 17 mm |
| Largest outer diameter in N200-series | 580 mm |
| Width range across N200-series | 12–92 mm |
| Bore position in N200-series (smallest first) | 9 of 35 |
| Bore above smallest N200-series size | 38 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| N211-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 55×100×21 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 N211 model number is decoded
For pure radial duty on a 55 mm shaft NTN supplies N211: two integral ribs on the inner ring and a ribless separable outer ring; the open execution is rated 6,900 r/min on grease and 8,200 r/min on oil. Digit by digit, N211 reads as N (inner ring ribbed, outer ring ribless), ISO 15 series, and bore 55 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. Minimum radial load matters: an unloaded N211 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Mass 626 g for the 55×100×21 mm N211 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of N211.
Typical equipment & failure modes
Common applications
- fan and blower rotor positions
- industrial gearbox input and output shafts
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- 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
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- hard-particle indentation of raceways in unfiltered oil or open arrangements
Selection pitfalls — read before you substitute
- On this 55 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 N211.
- The 21 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 55 mm inner ring.
- The N rib arrangement is not interchangeable with another prefix on the same 55 mm seat: inner ring ribbed, outer ring ribless. Swapping NU for NJ changes axial location behaviour even though the 100×21 mm envelope matches.
- The 22.5 mm section at 55 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 21 mm-wide cavity.
- Do not replace N211 with a deep-groove ball bearing on rating alone: line contact gives 64.5 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
- The 64.5/62.5 kN ratings, 7.6 kN Pu and 626 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N211 (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 N211?
N211 is an NTN N single-row cylindrical roller bearing to ISO 15: 55 mm bore, 100 mm OD and 21 mm width (2.165 × 3.937 × 0.827 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 64.5 kN, C0 62.5 kN, Pu 7.6 kN, grease limiting speed 6,900 r/min, oil 8,200 r/min, mass about 626 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. N211 is two integral ribs on the inner ring and a ribless separable outer ring — equivalent float behaviour with the separable ring on the housing side.
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. N211 is listed among the ＊ ULTAGE-marked executions in 2203E.
Can N211 take axial load and locate a shaft?
the N design is non-locating like NU but floats with the separable outer ring in the housing. 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 N211?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 66.5 mm, Ew 88.5 mm. The nominal bore/OD remain 55/100 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 6,900 r/min grease / 8,200 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.