231-560B bearing: complete specifications & equivalents
The 231-560B is a ISO 15 radial bearing sized 560 x 920 x 280 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 560 mm |
| Outer diameter D | 920 mm |
| Width B | 280 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 8550 kN |
| Basic static load rating C0 | 15500 kN |
| Fatigue load limit Pu | 1000 kN |
| Limiting speed (mechanical) | 280 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 752000 g |
| Manufacturer designation | NTN 231/560B |
| 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 & 23100-series range
| Bore d | 22.047 in |
|---|---|
| Outer diameter D | 36.22 in |
| Width B | 11.024 in |
| ISO bore code | 31 |
| Radial section height (D−d)/2 | 180 mm |
| Smallest bore in 23100-series | 100 mm |
| Largest outer diameter in 23100-series | 1420 mm |
| Width range across 23100-series | 52–412 mm |
| Bore position in 23100-series (smallest first) | 28 of 36 |
| Bore above smallest 23100-series size | 460 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 231-560BK | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23100-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 231-560BK (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 231-560B model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 231/560B denotes the 560 mm bore spherical roller bearing (8550 kN C / 15500 kN C0) in the 23100 series, the self-aligning choice for heavy combined load. Digit by digit the code reads as spherical-roller dimension series plus 560 mm bore; the 280 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. NTN prints two speeds for 231/560B: 280 r/min grease and 370 r/min oil — the gap of 90 r/min reflects oil cooling of the heavy roller set. Catalogue mass 752000 g (752.00 kg) for the 560×920×280 mm execution includes the basic cage and both roller rows; shaft and housing shoulders must support that ring squarely. Fit the cylindrical-bore 231/560B with the inner ring heated (max 120 °C) for the shaft interference; the outer ring slides into the housing with its spherical seat able to pivot after seating.
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
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 560 mm bore 231/560B 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.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 8550 kN rating no longer applies.
- Do not confuse EA and EM at the same number: 231/560B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 560×920 mm envelope is identical.
- Never substitute 231/560B by envelope alone: the 15500 kN C0 and 1000 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Oil relubrication toward 370 r/min needs drain and level design; flooding the 280 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 8550/15500 kN ratings, 1000 kN Pu and 752000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 231/560B (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 231/560B?
231/560B is an NTN double-row spherical roller bearing to ISO 15: 560 mm bore, 920 mm OD and 280 mm width (22.047 × 36.22 × 11.024 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 8550 kN, C0 15500 kN, Pu 1000 kN, grease limiting speed 280 r/min, oil 370 r/min, mass about 752000 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?
231/560B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 231/560BK (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. 231/560B is the basic execution.
What do D1 and W33 mean on 231/560B?
231/560B 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 231/560B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23100 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 8550 kN C / 15500 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.