240-900BK30 bearing: complete specifications & equivalents
The 240-900BK30 is a ISO 15 radial bearing sized 900 x 1280 x 375 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 900 mm |
| Outer diameter D | 1280 mm |
| Width B | 375 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 14700 kN |
| Basic static load rating C0 | 33500 kN |
| Fatigue load limit Pu | 1580 kN |
| Limiting speed (mechanical) | 170 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1540000 g |
| Manufacturer designation | NTN 240/900BK30 |
| 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 & 24000-series range
| Bore d | 35.433 in |
|---|---|
| Outer diameter D | 50.394 in |
| Width B | 14.764 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 190 mm |
| Smallest bore in 24000-series | 65 mm |
| Largest outer diameter in 24000-series | 1580 mm |
| Width range across 24000-series | 35–462 mm |
| Bore position in 24000-series (smallest first) | 38 of 42 |
| Bore above smallest 24000-series size | 835 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 240-900B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 240-900B — mounting (adapter/withdrawal sleeve or tapered seat, drive-up) differs. Verify shaft arrangement. |
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 240-900BK30 model number is decoded
For heavy radial load with misalignment on a 900 mm shaft, NTN supplies 240/900BK30: sphered outer raceway, two roller rows, pressed-steel cage (standard execution), oil speed 220 r/min. Digit by digit the code reads as spherical-roller dimension series plus 900 mm bore; the 375 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. The sphered outer raceway lets the inner-ring assembly pivot, accommodating shaft deflection and housing misalignment (around 1–2° for this class; use the 2203E value for the exact series) without edge loading the rollers. The 190.0 mm section height hosts the spherical roller geometry; shaft and housing fillet radii must clear the chamfer table so the 375 mm-wide ring seats fully on both sides. Supply grease through the outer-ring feature during commissioning and at the calculated interval, rotating the 900 mm bore assembly by hand to distribute it across both rows.
Typical equipment & failure modes
Common applications
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- pressed EA cage fatigue under sustained vibration when minimum load is not maintained
- roller-end smearing during skidding starts under light load and high viscosity grease
- water-induced pitting in washdown or outdoor duty without effective external seals
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 900 mm bore 240/900BK30 is normally mounted on adapter/withdrawal sleeves with hydraulic assistance; follow the NTN drive-up angle or oil-injection procedure — manual nut tightening cannot set the multi-tonne seating correctly.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 240/900BK30 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 240/900BK30 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Minimum load must be maintained even at rest under vibration: an unloaded 240/900BK30 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- Minimum load must be maintained even at rest under vibration: an unloaded 240/900BK30 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The 14700/33500 kN ratings, 1580 kN Pu and 1540000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/900BK30 (basic); another maker's same-envelope part revises internal geometry, so re-verify ratings and cage before substitution on vibrating or rated drives.
Frequently asked questions
What are the dimensions and catalogue data of 240/900BK30?
240/900BK30 is an NTN double-row spherical roller bearing to ISO 15: 900 mm bore, 1280 mm OD and 375 mm width (35.433 × 50.394 × 14.764 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 14700 kN, C0 33500 kN, Pu 1580 kN, grease limiting speed 170 r/min, oil 220 r/min, mass about 1540000 g. It is open, with pressed-steel cage (standard execution) and a 1:30 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K30 denotes a 1:30 tapered bore (the wide 24000 series). 240/900BK30 mounts on a matching adapter or withdrawal sleeve on a plain 900 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 240/900B.
What do EA and EM mean on NTN spherical roller bearings?
EA is the NTN standard-capacity/high-capacity execution with a pressed sheet-steel window cage; EM is the high-capacity execution with a one-piece machined brass cage. Both use the optimised symmetric-roller design, but cage identity changes mass, speed behaviour and suitability for duties like vibrating screens, so they are separate order numbers. 240/900BK30 is the basic execution.
What do D1 and W33 mean on 240/900BK30?
240/900BK30 is listed without a D1/W33 outer-ring groove in 2203E; lubrication is supplied from the ring sides. D1 (NTN spelling) and W33 add the annular groove plus holes and are ordered as distinct suffixed executions of the same envelope.
How much misalignment and axial load can 240/900BK30 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 14700 kN C / 33500 kN C0 — but sustained pure axial load is not recommended because it unloads one row.
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.