239-750K bearing: complete specifications & equivalents
The 239-750K is a ISO 15 radial bearing sized 750 x 1000 x 185 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 750 mm |
| Outer diameter D | 1000 mm |
| Width B | 185 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 5600 kN |
| Basic static load rating C0 | 13000 kN |
| Fatigue load limit Pu | 990 kN |
| Limiting speed (mechanical) | 260 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 399000 g |
| Manufacturer designation | NTN 239/750K |
| 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 | 29.528 in |
|---|---|
| Outer diameter D | 39.37 in |
| Width B | 7.283 in |
| ISO bore code | 39 |
| Radial section height (D−d)/2 | 125 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) | 27 of 38 |
| Bore above smallest 23900-series size | 590 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 239-750 | 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 239-750 — 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 239-750K model number is decoded
The NTN order number 239/750K identifies a 750×1000×185 mm (29.528 × 39.37 × 7.283 in) spherical roller bearing, 1:12 tapered bore (K), to the ISO 15 boundary plan. Numbering ties 239/750K to its envelope and execution: same-number EA versus EM or plain variants share the 750 mm bore but differ in cage and sometimes mass, so they are quoted as separate articles. The 125.0 mm radial section over the 750 mm bore carries two roller rows; capacity per millimetre of bore is about 7.5 kN/mm, among the highest of rolling bearings for the ISO 15 envelope. Selection: the C0/C ratio of 2.32 (13000/5600 kN) reflects the heavy static and shock proportioning of 239/750K; size the equivalent load at the required L10 with shock factor for the application. Fillet radii on shaft and housing must clear the ring chamfers of the 185 mm-wide set; use the NTN shoulder/withdrawal-groove table rather than copying a ball-bearing layout.
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
- water-induced pitting in washdown or outdoor duty without effective external seals
- hard-particle indentation through the open arrangement in dusty mining duty
Selection pitfalls — read before you substitute
- At 750 mm bore 239/750K 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 750 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Oil relubrication toward 340 r/min needs drain and level design; flooding the 185 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 1:12 tapered bore is the only difference from the cylindrical-bore 239/750: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- The 1:12 tapered bore is the only difference from the cylindrical-bore 239/750: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- The 5600/13000 kN ratings, 990 kN Pu and 399000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 239/750K (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 239/750K?
239/750K is an NTN double-row spherical roller bearing to ISO 15: 750 mm bore, 1000 mm OD and 185 mm width (29.528 × 39.37 × 7.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 5600 kN, C0 13000 kN, Pu 990 kN, grease limiting speed 260 r/min, oil 340 r/min, mass about 399000 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. 239/750K 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 239/750.
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. 239/750K is the basic execution.
What do D1 and W33 mean on 239/750K?
239/750K 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 239/750K 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 — 5600 kN C / 13000 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.