NU244 bearing: complete specifications & equivalents
The NU244 is a ISO 15 radial bearing sized 220 x 400 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 400 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 845 kN |
| Basic static load rating C0 | 1080 kN |
| Fatigue load limit Pu | 94 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 37000 g |
| Manufacturer designation | NTN NU244 |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 2.559 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 90 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) | 31 of 36 |
| Bore above smallest NU200-series size | 205 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NU244-ECML | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 220×400×65 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 NU244 model number is decoded
NU244 is the standard section of the NTN NU200 dimension series for a 220 mm shaft — 845 kN of basic dynamic capacity in a 37000 g, open bearing. On the NTN nameplate NU states which ring carries the ribs, which determines whether NU244 floats or locates; the numeric remainder is the ISO 15 series and 220 mm bore reference, not a fit or clearance instruction. Line contact between rollers and raceways gives NU244 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. The 220 mm (8.661 in) bore and 400 mm (15.748 in) OD are ISO 15 boundary values; fillet and shoulder dimensions must still come from the NTN mounting table for the 65 mm-wide ring. Keep the open bearing wrapped until fitting: the line-contact raceways of the 220 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.
Typical equipment & failure modes
Common applications
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
- wind-turbine gearbox planet and rotor shafts
- ship propulsion line shafts and reduction gears
Known failure patterns
- inner-ring raceway spalling from overload in the line-contact Hertzian zone
- cage distortion after a mounting blow carried through the roller set
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- At 220 mm bore, oil-lubricated arrangements toward 1,900 r/min need positive flow and drain design; the 37000 g NU244 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded NU244 skids at 1,600 r/min and fails by smearing long before L10 fatigue.
- The 65 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 220 mm inner ring.
- The 90.0 mm section at 220 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 65 mm-wide cavity.
- Wide (22/23) and light (10/49) executions at 220 mm bore share bore but not OD/width; check the full NU200 series code before substituting, because housing and shoulder geometry will not interchange.
- The 845/1080 kN ratings, 94 kN Pu and 37000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU244 (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 NU244?
NU244 is an NTN NU single-row cylindrical roller bearing to ISO 15: 220 mm bore, 400 mm OD and 65 mm width (8.661 × 15.748 × 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 845 kN, C0 1080 kN, Pu 94 kN, grease limiting speed 1,600 r/min, oil 1,900 r/min, mass about 37000 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. NU244 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. NU244 is supplied in the standard open execution shown in the table.
Can NU244 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 NU244?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 270 mm, Ew 350 mm. The nominal bore/OD remain 220/400 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 1,600 r/min grease / 1,900 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.