231-600BK bearing: complete specifications & equivalents
The 231-600BK 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 | 880000 g |
| Manufacturer designation | NTN 231/600BK |
| 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 |
|---|---|---|---|
| 231-600B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23100-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 231-600B — 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 231-600BK model number is decoded
231/600BK belongs to the 23100 series of NTN spherical rollers: self-aligning, high radial capacity, moderate axial load in either direction. Digit by digit the code reads as spherical-roller dimension series plus 600 mm bore; the 300 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. Pu 1160 kN is the catalogue fatigue load limit for 231/600BK, used in the adjusted-life equation at contaminated or partial-film conditions typical of mining and vibrating duty. Catalogue mass 880000 g (880.00 kg) for the 600×980×300 mm execution includes the basic cage and both roller rows; shaft and housing shoulders must support that ring squarely. Check the self-aligning movement after fitting: the housing should pivot freely around the sphered outer raceway; a pinched outer ring removes the alignment capacity the bearing was selected for.
Typical equipment & failure modes
Common applications
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
Known failure patterns
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- 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
- hard-particle indentation through the open arrangement in dusty mining duty
- brinelling from static overload or a hammer blow during sleeve mounting
Selection pitfalls — read before you substitute
- At 600 mm bore 231/600BK 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.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 300 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 231/600BK in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 600 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 231/600BK in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The 10000/18400 kN ratings, 1160 kN Pu and 880000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 231/600BK (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 231/600BK?
231/600BK 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 880000 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. 231/600BK 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 231/600B.
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. 231/600BK is the basic execution.
What do D1 and W33 mean on 231/600BK?
231/600BK 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 231/600BK 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.