239-900K bearing: complete specifications & equivalents
The 239-900K is a ISO 15 radial bearing sized 900 x 1180 x 206 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 | 1180 mm |
| Width B | 206 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 7400 kN |
| Basic static load rating C0 | 17300 kN |
| Fatigue load limit Pu | 1230 kN |
| Limiting speed (mechanical) | 210 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 603000 g |
| Manufacturer designation | NTN 239/900K |
| 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 | 35.433 in |
|---|---|
| Outer diameter D | 46.457 in |
| Width B | 8.11 in |
| ISO bore code | 39 |
| Radial section height (D−d)/2 | 140 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) | 30 of 38 |
| Bore above smallest 23900-series size | 740 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 239-900 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 239-900 — 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 239-900K model number is decoded
The NTN order number 239/900K identifies a 900×1180×206 mm (35.433 × 46.457 × 8.11 in) spherical roller bearing, 1:12 tapered bore (K), to the ISO 15 boundary plan. On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (K), lubrication feature (none); 239/900K is assembled exactly in that order. Open by design, 239/900K requires application seals and a grease or oil system; NTN vibrating-duty executions of this envelope are selected with cage and clearance choices that are separate order codes. Equivalent-load planning keeps a radial plus moderate axial combination on 239/900K; if the axial component dominates, pair with a thrust bearing rather than running one roller row unloaded. On vibrating-duty shafts verify the radial clearance class and cage choice at order time; the open 239/900K leaves sealing and the C3/C4 clearance decision to the application drawing.
Typical equipment & failure modes
Common applications
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
- brinelling from static overload or a hammer blow during sleeve mounting
Selection pitfalls — read before you substitute
- At 900 mm bore 239/900K 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 270 r/min needs drain and level design; flooding the 206 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 270 r/min needs drain and level design; flooding the 206 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 7400 kN rating no longer applies.
- The 7400/17300 kN ratings, 1230 kN Pu and 603000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 239/900K (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 239/900K?
239/900K is an NTN double-row spherical roller bearing to ISO 15: 900 mm bore, 1180 mm OD and 206 mm width (35.433 × 46.457 × 8.11 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7400 kN, C0 17300 kN, Pu 1230 kN, grease limiting speed 210 r/min, oil 270 r/min, mass about 603000 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. 239/900K 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 239/900.
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. 239/900K is the basic execution.
What do D1 and W33 mean on 239/900K?
239/900K 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 239/900K 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 — 7400 kN C / 17300 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.