240-900B bearing: complete specifications & equivalents
The 240-900B 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 | 1570000 g |
| Manufacturer designation | NTN 240/900B |
| 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 |
|---|---|---|---|
| 240-900BK30 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 240-900BK30 (K/K30 sleeve or tapered-seat mounting). 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 240-900B model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 240/900B denotes the 900 mm bore spherical roller bearing (14700 kN C / 33500 kN C0) in the 24000 series, the self-aligning choice for heavy combined load. 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. NTN prints two speeds for 240/900B: 170 r/min grease and 220 r/min oil — the gap of 50 r/min reflects oil cooling of the heavy roller set. Grease/oil ratio: the 170 r/min limiting value is .77 of the 220 r/min oil value; heavy 375 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Fit the cylindrical-bore 240/900B with the inner ring heated (max 120 °C) for the shaft interference; the outer ring slides into the housing with its spherical seat able to pivot after seating.
Typical equipment & failure modes
Common applications
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
Known failure patterns
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- water-induced pitting in washdown or outdoor duty without effective external seals
- brinelling from static overload or a hammer blow during sleeve mounting
Selection pitfalls — read before you substitute
- At 900 mm bore 240/900B 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.
- K and K30 are different tapers — K is 1:12 and K30 is 1:30 on the wide series; an adapter sleeve for one will not mount the other 900 mm bearing, and drive-up procedures differ.
- Do not confuse EA and EM at the same number: 240/900B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 900×1280 mm envelope is identical.
- Never substitute 240/900B by envelope alone: the 33500 kN C0 and 1580 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Oil relubrication toward 220 r/min needs drain and level design; flooding the 375 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 14700/33500 kN ratings, 1580 kN Pu and 1570000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/900B (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 240/900B?
240/900B 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 1570000 g. It is open, with pressed-steel cage (standard execution).
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
240/900B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 240/900BK30 (K = 1:12, or K30 = 1:30 on the wide series), intended for adapter/withdrawal-sleeve mounting.
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. 240/900B is the basic execution.
What do D1 and W33 mean on 240/900B?
240/900B 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 240/900B 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.