NF211EA bearing: complete specifications & equivalents
The NF211EA 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, stamped ribbon (J-type) |
| Basic dynamic load rating C | 102 kN |
| Basic static load rating C0 | 98.5 kN |
| Fatigue load limit Pu | 12 kN |
| Limiting speed (mechanical) | 6300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 635 g |
| Manufacturer designation | NTN NF211EA |
| 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 & NF200-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 0.827 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in NF200-series | 20 mm |
| Largest outer diameter in NF200-series | 580 mm |
| Width range across NF200-series | 14–92 mm |
| Bore position in NF200-series (smallest first) | 8 of 34 |
| Bore above smallest NF200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NF211EA | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 NF211EA model number is decoded
NTN lists NF211EA on the 55×100 mm envelope, 21 mm wide: a line-contact radial bearing with the EA high-capacity pressed sheet-steel cage and a grease limiting speed of 6,300 r/min. Digit by digit, NF211EA reads as NF (one rib on each ring), 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. The 22.5 mm radial section ((100−55)/2) frames the roller complement; capacity per millimetre of bore is about 1.9 kN/mm before application factors. Mass 635 g for the 55×100×21 mm NF211EA execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Keep the open bearing wrapped until fitting: the line-contact raceways of the 55 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
Typical equipment & failure modes
Common applications
- industrial gearbox input and output shafts
- medium electric-motor and generator shafts
- pump and compressor crankshafts and rotors
- machine-tool gearbox and spindle radial sets
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
- brinelling from static overload or impact during handling
- false brinelling on standby machines exposed to external vibration
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 NF211EA.
- If the shaft must be located both ways, do not use NF211EA alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 100 mm race brinells and releases as vibration within hours.
- The NF rib arrangement is not interchangeable with another prefix on the same 55 mm seat: one rib on each ring. 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 EA pressed-steel-cage cage the relubrication groove and oil-level design must keep grease from churning in the 21 mm-wide cavity.
- The 102/98.5 kN ratings, 12 kN Pu and 635 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NF211EA (EA pressed-steel-cage 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 NF211EA?
NF211EA is an NTN NF 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 102 kN, C0 98.5 kN, Pu 12 kN, grease limiting speed 6,300 r/min, oil 8,900 r/min, mass about 635 g. It is open, with the EA high-capacity 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. NF211EA is one integral rib on each ring — separable inner ring with single-direction axial guidance and a defined shaft position.
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. This page's bearing carries the EA pressed-steel-cage execution.
Can NF211EA take axial load and locate a shaft?
the NF design gives one-direction axial guidance via its single outer-ring rib. 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 NF211EA?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 66 mm, Ew 90 mm. The nominal bore/OD remain 55/100 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 6,300 r/min grease / 8,900 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.