230-950B bearing: complete specifications & equivalents
The 230-950B is a ISO 15 radial bearing sized 950 x 1360 x 300 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 950 mm |
| Outer diameter D | 1360 mm |
| Width B | 300 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 12800 kN |
| Basic static load rating C0 | 28400 kN |
| Fatigue load limit Pu | 1750 kN |
| Limiting speed (mechanical) | 180 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1430000 g |
| Manufacturer designation | NTN 230/950B |
| 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 | 37.402 in |
|---|---|
| Outer diameter D | 53.543 in |
| Width B | 11.811 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 205 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) | 43 of 46 |
| Bore above smallest 23000-series size | 880 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 230-950BK | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 230-950BK (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 230-950B model number is decoded
The NTN order number 230/950B identifies a 950×1360×300 mm (37.402 × 53.543 × 11.811 in) spherical roller bearing, cylindrical bore, to the ISO 15 boundary plan. Reading the full code: the number gives the 950×1360 mm envelope, — names the cage/capacity execution, no bore suffix means cylindrical bore for a direct shaft seat, and plain outer ring (no D1/W33 groove) completes the order number. The plain outer ring (no D1/W33 groove) makes relubrication part of the design: fresh grease reaches the rolling elements through the outer-ring feature rather than relying solely on end-side packing. Selection: the C0/C ratio of 2.22 (28400/12800 kN) reflects the heavy static and shock proportioning of 230/950B; size the equivalent load at the required L10 with shock factor for the application. Check the self-aligning movement after fitting: the housing should pivot freely around the sphered outer raceway; a pinched outer ring removes the alignment capacity the bearing was selected for.
Typical equipment & failure modes
Common applications
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- rolling-contact fatigue after the catalogue L10 life at the actual load
- rolling-contact fatigue after the catalogue L10 life at the actual load
Selection pitfalls — read before you substitute
- At 950 mm bore 230/950B 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 230/950B in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Do not confuse EA and EM at the same number: 230/950B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 950×1360 mm envelope is identical.
- The cylindrical-bore 230/950B and its tapered-bore counterpart 230/950BK share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- 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 950 mm bearing, and drive-up procedures differ.
- The 12800/28400 kN ratings, 1750 kN Pu and 1430000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 230/950B (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 230/950B?
230/950B is an NTN double-row spherical roller bearing to ISO 15: 950 mm bore, 1360 mm OD and 300 mm width (37.402 × 53.543 × 11.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 12800 kN, C0 28400 kN, Pu 1750 kN, grease limiting speed 180 r/min, oil 230 r/min, mass about 1430000 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?
230/950B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 230/950BK (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. 230/950B is the basic execution.
What do D1 and W33 mean on 230/950B?
230/950B 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 230/950B 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 — 12800 kN C / 28400 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.