239-950 bearing: complete specifications & equivalents
The 239-950 is a ISO 15 radial bearing sized 950 x 1250 x 224 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 | 1250 mm |
| Width B | 224 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 8650 kN |
| Basic static load rating C0 | 20500 kN |
| Fatigue load limit Pu | 1390 kN |
| Limiting speed (mechanical) | 190 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 774000 g |
| Manufacturer designation | NTN 239/950 |
| 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 & 23900-series range
| Bore d | 37.402 in |
|---|---|
| Outer diameter D | 49.213 in |
| Width B | 8.819 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 150 mm |
| Smallest bore in 23900-series | 160 mm |
| Largest outer diameter in 23900-series | 1820 mm |
| Width range across 23900-series | 45–315 mm |
| Bore position in 23900-series (smallest first) | 31 of 38 |
| Bore above smallest 23900-series size | 790 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 239-950K | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 239-950K (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 239-950 model number is decoded
The NTN order number 239/950 identifies a 950×1250×224 mm (37.402 × 49.213 × 8.819 in) spherical roller bearing, cylindrical bore, to the ISO 15 boundary plan. Reading the full code: the number gives the 950×1250 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 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. Equivalent-load planning keeps a radial plus moderate axial combination on 239/950; if the axial component dominates, pair with a thrust bearing rather than running one roller row unloaded. Supply grease through the outer-ring feature during commissioning and at the calculated interval, rotating the 950 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
- cage damage when a mounting force is applied through the roller set instead of the ring face
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
- false brinelling on stopped machines exposed to screen or crusher vibration
Selection pitfalls — read before you substitute
- At 950 mm bore 239/950 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.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 950 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Minimum load must be maintained even at rest under vibration: an unloaded 239/950 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 950 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Minimum load must be maintained even at rest under vibration: an unloaded 239/950 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The 8650/20500 kN ratings, 1390 kN Pu and 774000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 239/950 (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 239/950?
239/950 is an NTN double-row spherical roller bearing to ISO 15: 950 mm bore, 1250 mm OD and 224 mm width (37.402 × 49.213 × 8.819 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8650 kN, C0 20500 kN, Pu 1390 kN, grease limiting speed 190 r/min, oil 250 r/min, mass about 774000 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?
239/950 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 239/950K (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. 239/950 is the basic execution.
What do D1 and W33 mean on 239/950?
239/950 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 239/950 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23900 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 8650 kN C / 20500 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.