230-900BK bearing: complete specifications & equivalents
The 230-900BK is a ISO 15 radial bearing sized 900 x 1280 x 280 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 | 280 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 11400 kN |
| Basic static load rating C0 | 24700 kN |
| Fatigue load limit Pu | 1580 kN |
| Limiting speed (mechanical) | 190 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1130000 g |
| Manufacturer designation | NTN 230/900BK |
| 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 & 23000-series range
| Bore d | 35.433 in |
|---|---|
| Outer diameter D | 50.394 in |
| Width B | 11.024 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 190 mm |
| Smallest bore in 23000-series | 70 mm |
| Largest outer diameter in 23000-series | 1580 mm |
| Width range across 23000-series | 27–345 mm |
| Bore position in 23000-series (smallest first) | 42 of 46 |
| Bore above smallest 23000-series size | 830 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 230-900B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23000-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 230-900B — 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 230-900BK model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 230/900BK denotes the 900 mm bore spherical roller bearing (11400 kN C / 24700 kN C0) in the 23000 series, the self-aligning choice for heavy combined load. On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (K), lubrication feature (none); 230/900BK is assembled exactly in that order. NTN prints two speeds for 230/900BK: 190 r/min grease and 250 r/min oil — the gap of 60 r/min reflects oil cooling of the heavy roller set. Speed planning: 190 r/min grease limiting speed is the cage/kinematic ceiling and 250 r/min is the oil-lubricated value for the 900 mm bore; vibrating screens rarely approach either and are load/cage limited instead. 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
- 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
- roller-end smearing during skidding starts under light load and high viscosity grease
- brinelling from static overload or a hammer blow during sleeve mounting
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 900 mm bore 230/900BK 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.
- Oil relubrication toward 250 r/min needs drain and level design; flooding the 280 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Oil relubrication toward 250 r/min needs drain and level design; flooding the 280 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 900 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Oil relubrication toward 250 r/min needs drain and level design; flooding the 280 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 11400/24700 kN ratings, 1580 kN Pu and 1130000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 230/900BK (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 230/900BK?
230/900BK is an NTN double-row spherical roller bearing to ISO 15: 900 mm bore, 1280 mm OD and 280 mm width (35.433 × 50.394 × 11.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 11400 kN, C0 24700 kN, Pu 1580 kN, grease limiting speed 190 r/min, oil 250 r/min, mass about 1130000 g. It is open, with pressed-steel cage (standard execution) and a 1:12 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K denotes a 1:12 tapered bore. 230/900BK mounts on an adapter sleeve (or tapered shaft seat) and is driven up to the specified residual clearance; its cylindrical-bore counterpart in the same envelope and ratings is 230/900B.
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. 230/900BK is the basic execution.
What do D1 and W33 mean on 230/900BK?
230/900BK 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 230/900BK take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 11400 kN C / 24700 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.