231-530B bearing: complete specifications & equivalents
The 231-530B is a ISO 15 radial bearing sized 530 x 870 x 272 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 530 mm |
| Outer diameter D | 870 mm |
| Width B | 272 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 7800 kN |
| Basic static load rating C0 | 14200 kN |
| Fatigue load limit Pu | 920 kN |
| Limiting speed (mechanical) | 310 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 653000 g |
| Manufacturer designation | NTN 231/530B |
| 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 | 20.866 in |
|---|---|
| Outer diameter D | 34.252 in |
| Width B | 10.709 in |
| ISO bore code | 31 |
| Radial section height (D−d)/2 | 170 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) | 27 of 36 |
| Bore above smallest 23100-series size | 430 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 231-530BK | 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 231-530BK (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 231-530B model number is decoded
NTN lists 231/530B with a cylindrical bore and plain outer ring (no D1/W33 groove): 530 mm bore, 870 mm OD, 272 mm width, rated 310 r/min on grease. The leading digits are the ISO 15 dimension series (23100 series); the bore code resolves to 530 mm (two-digit code ×5, with the 00–03 exception table), and 870 mm OD / 272 mm width follow the general plan. The cylindrical bore fits a machined 530 mm shaft seat directly; the same envelope in 231/530BK (tapered) is the sleeve-mounted alternative when clearance must be set by drive-up. Pu 920 kN against C0 14200 kN anchors the contamination derating; for dirty mining duty the adjusted life of 231/530B moves with cleanliness far more than with small C variations. 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
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
Known failure patterns
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- 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
- 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 530 mm bore 231/530B 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 272 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The cylindrical-bore 231/530B and its tapered-bore counterpart 231/530BK share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- The cylindrical-bore 231/530B and its tapered-bore counterpart 231/530BK share envelope and ratings but not mounting: do not order the K variant unless the drawing specifies a sleeve or tapered seat.
- Do not confuse EA and EM at the same number: 231/530B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 530×870 mm envelope is identical.
- The 7800/14200 kN ratings, 920 kN Pu and 653000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 231/530B (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 231/530B?
231/530B is an NTN double-row spherical roller bearing to ISO 15: 530 mm bore, 870 mm OD and 272 mm width (20.866 × 34.252 × 10.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7800 kN, C0 14200 kN, Pu 920 kN, grease limiting speed 310 r/min, oil 400 r/min, mass about 653000 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?
231/530B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 231/530BK (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. 231/530B is the basic execution.
What do D1 and W33 mean on 231/530B?
231/530B 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 231/530B 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 — 7800 kN C / 14200 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.