240-530BK30 bearing: complete specifications & equivalents
The 240-530BK30 is a ISO 15 radial bearing sized 530 x 780 x 250 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 | 780 mm |
| Width B | 250 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 6200 kN |
| Basic static load rating C0 | 12700 kN |
| Fatigue load limit Pu | 700 kN |
| Limiting speed (mechanical) | 330 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 406000 g |
| Manufacturer designation | NTN 240/530BK30 |
| 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 & 24000-series range
| Bore d | 20.866 in |
|---|---|
| Outer diameter D | 30.709 in |
| Width B | 9.843 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 125 mm |
| Smallest bore in 24000-series | 65 mm |
| Largest outer diameter in 24000-series | 1580 mm |
| Width range across 24000-series | 35–462 mm |
| Bore position in 24000-series (smallest first) | 29 of 42 |
| Bore above smallest 24000-series size | 465 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 240-530B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 240-530B — 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 240-530BK30 model number is decoded
240/530BK30 is an NTN double-row spherical roller bearing: two rows of symmetric rollers on a sphered outer raceway, 530×780×250 mm to ISO 15, with pressed-steel cage (standard execution). The leading digits are the ISO 15 dimension series (24000 series); the bore code resolves to 530 mm (two-digit code ×5, with the 00–03 exception table), and 780 mm OD / 250 mm width follow the general plan. 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. Equivalent-load planning keeps a radial plus moderate axial combination on 240/530BK30; if the axial component dominates, pair with a thrust bearing rather than running one roller row unloaded. Mount 240/530BK30 on its adapter or withdrawal sleeve on the 530 mm plain shaft: oil the sleeve, fit the lock nut, drive up to the NTN-specified residual clearance (or use oil injection on large seats), then lock the tab washer.
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
- 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
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
Selection pitfalls — read before you substitute
- At 530 mm bore 240/530BK30 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.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 530 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 530 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 330 r/min grease rating is lost to abrasive wear long before fatigue.
- 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 530 mm bearing, and drive-up procedures differ.
- The 6200/12700 kN ratings, 700 kN Pu and 406000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/530BK30 (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 240/530BK30?
240/530BK30 is an NTN double-row spherical roller bearing to ISO 15: 530 mm bore, 780 mm OD and 250 mm width (20.866 × 30.709 × 9.843 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 6200 kN, C0 12700 kN, Pu 700 kN, grease limiting speed 330 r/min, oil 430 r/min, mass about 406000 g. It is open, with pressed-steel cage (standard execution) and a 1:30 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K30 denotes a 1:30 tapered bore (the wide 24000 series). 240/530BK30 mounts on a matching adapter or withdrawal sleeve on a plain 530 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 240/530B.
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. 240/530BK30 is the basic execution.
What do D1 and W33 mean on 240/530BK30?
240/530BK30 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 240/530BK30 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 6200 kN C / 12700 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.