230-750B bearing: complete specifications & equivalents
The 230-750B is a ISO 15 radial bearing sized 750 x 1090 x 250 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 | 1090 mm |
| Width B | 250 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 9100 kN |
| Basic static load rating C0 | 18300 kN |
| Fatigue load limit Pu | 1290 kN |
| Limiting speed (mechanical) | 250 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 790000 g |
| Manufacturer designation | NTN 230/750B |
| 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 | 29.528 in |
|---|---|
| Outer diameter D | 42.913 in |
| Width B | 9.843 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 170 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) | 39 of 46 |
| Bore above smallest 23000-series size | 680 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 230-750BK | 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 230-750BK (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 230-750B model number is decoded
NTN lists 230/750B with a cylindrical bore and plain outer ring (no D1/W33 groove): 750 mm bore, 1090 mm OD, 250 mm width, rated 250 r/min on grease. Numbering ties 230/750B 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 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. With about 12.1 kN of C per millimetre of the 750 mm bore, 230/750B screens interchange candidates quickly — then verify cage (EA/EM), bore (K/K30) and lubrication feature (D1/W33) suffixes. Supply grease through the outer-ring feature during commissioning and at the calculated interval, rotating the 750 mm bore assembly by hand to distribute it across both rows.
Typical equipment & failure modes
Common applications
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
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
- roller-end smearing during skidding starts under light load and high viscosity grease
- false brinelling on stopped machines exposed to screen or crusher vibration
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 750 mm bore 230/750B 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.
- Do not confuse EA and EM at the same number: 230/750B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 750×1090 mm envelope is identical.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 9100 kN rating no longer applies.
- Never substitute 230/750B by envelope alone: the 18300 kN C0 and 1290 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- 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 750 mm bearing, and drive-up procedures differ.
- The 9100/18300 kN ratings, 1290 kN Pu and 790000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 230/750B (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 230/750B?
230/750B is an NTN double-row spherical roller bearing to ISO 15: 750 mm bore, 1090 mm OD and 250 mm width (29.528 × 42.913 × 9.843 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 9100 kN, C0 18300 kN, Pu 1290 kN, grease limiting speed 250 r/min, oil 320 r/min, mass about 790000 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?
230/750B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 230/750BK (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. 230/750B is the basic execution.
What do D1 and W33 mean on 230/750B?
230/750B 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 230/750B 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 — 9100 kN C / 18300 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.