231-710BK bearing: complete specifications & equivalents
The 231-710BK is a ISO 15 radial bearing sized 710 x 1150 x 345 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 710 mm |
| Outer diameter D | 1150 mm |
| Width B | 345 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 13000 kN |
| Basic static load rating C0 | 24900 kN |
| Fatigue load limit Pu | 1470 kN |
| Limiting speed (mechanical) | 220 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1380000 g |
| Manufacturer designation | NTN 231/710BK |
| 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 | 27.953 in |
|---|---|
| Outer diameter D | 45.276 in |
| Width B | 13.583 in |
| ISO bore code | 31 |
| Radial section height (D−d)/2 | 220 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) | 32 of 36 |
| Bore above smallest 23100-series size | 610 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 231-710B | 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 231-710B — 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 231-710BK model number is decoded
The NTN order number 231/710BK identifies a 710×1150×345 mm (27.953 × 45.276 × 13.583 in) spherical roller bearing, 1:12 tapered bore (K), to the ISO 15 boundary plan. Reading the full code: the number gives the 710×1150 mm envelope, — names the cage/capacity execution, K marks the 1:12 tapered bore for adapter/withdrawal-sleeve mounting, and plain outer ring (no D1/W33 groove) completes the order number. Suffix reading on 231/710BK: the bare number is the standard open execution; K marks the 1:12 tapered bore; B marks the standard large-bore internal design on slash-size 230–232 series; quote the full code because each suffix is a distinct article. Equivalent-load planning keeps a radial plus moderate axial combination on 231/710BK; if the axial component dominates, pair with a thrust bearing rather than running one roller row unloaded. 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
- 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
- cage damage when a mounting force is applied through the roller set instead of the ring face
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- rolling-contact fatigue after the catalogue L10 life at the actual load
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 710 mm bore 231/710BK 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 345 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- Oil relubrication toward 280 r/min needs drain and level design; flooding the 345 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 231/710BK in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 345 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The 13000/24900 kN ratings, 1470 kN Pu and 1380000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 231/710BK (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 231/710BK?
231/710BK is an NTN double-row spherical roller bearing to ISO 15: 710 mm bore, 1150 mm OD and 345 mm width (27.953 × 45.276 × 13.583 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 13000 kN, C0 24900 kN, Pu 1470 kN, grease limiting speed 220 r/min, oil 280 r/min, mass about 1380000 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. 231/710BK 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 231/710B.
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. 231/710BK is the basic execution.
What do D1 and W33 mean on 231/710BK?
231/710BK 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 231/710BK 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 — 13000 kN C / 24900 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.