231-600B bearing: complete specifications & equivalents
The 231-600B is a ISO 15 radial bearing sized 600 x 980 x 300 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 600 mm |
| Outer diameter D | 980 mm |
| Width B | 300 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 10000 kN |
| Basic static load rating C0 | 18400 kN |
| Fatigue load limit Pu | 1160 kN |
| Limiting speed (mechanical) | 260 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 908000 g |
| Manufacturer designation | NTN 231/600B |
| 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 | 23.622 in |
|---|---|
| Outer diameter D | 38.583 in |
| Width B | 11.811 in |
| ISO bore code | 31 |
| Radial section height (D−d)/2 | 190 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) | 29 of 36 |
| Bore above smallest 23100-series size | 500 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 231-600BK | 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 231-600BK (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 231-600B model number is decoded
231/600B belongs to the 23100 series of NTN spherical rollers: self-aligning, high radial capacity, moderate axial load in either direction. Numbering ties 231/600B to its envelope and execution: same-number EA versus EM or plain variants share the 600 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. 600 mm bore is 23.622 in and 980 mm OD is 38.583 in; the ISO 15 envelope swaps between brands, but the 10000/18400 kN ratings and cage design are NTN 2203E values. After mounting on a tapered seat, lock the nut and re-check clearance after a short running-in period, because sleeve seating and ring lift-off can change the residual clearance of the 600 mm set.
Typical equipment & failure modes
Common applications
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- pressed EA cage fatigue under sustained vibration when minimum load is not maintained
- 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 600 mm bore 231/600B 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.
- Never substitute 231/600B by envelope alone: the 18400 kN C0 and 1160 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Oil relubrication toward 340 r/min needs drain and level design; flooding the 300 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 10000 kN rating no longer applies.
- 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 600 mm bearing, and drive-up procedures differ.
- The 10000/18400 kN ratings, 1160 kN Pu and 908000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 231/600B (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 231/600B?
231/600B is an NTN double-row spherical roller bearing to ISO 15: 600 mm bore, 980 mm OD and 300 mm width (23.622 × 38.583 × 11.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 10000 kN, C0 18400 kN, Pu 1160 kN, grease limiting speed 260 r/min, oil 340 r/min, mass about 908000 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?
231/600B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 231/600BK (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. 231/600B is the basic execution.
What do D1 and W33 mean on 231/600B?
231/600B 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 231/600B 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 — 10000 kN C / 18400 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.