240-500BK30 bearing: complete specifications & equivalents
The 240-500BK30 is a ISO 15 radial bearing sized 500 x 720 x 218 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 500 mm |
| Outer diameter D | 720 mm |
| Width B | 218 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 5300 kN |
| Basic static load rating C0 | 10900 kN |
| Fatigue load limit Pu | 640 kN |
| Limiting speed (mechanical) | 350 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 290000 g |
| Manufacturer designation | NTN 240/500BK30 |
| 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 | 19.685 in |
|---|---|
| Outer diameter D | 28.346 in |
| Width B | 8.583 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 110 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) | 28 of 42 |
| Bore above smallest 24000-series size | 435 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 240-500B | 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 240-500B — 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 240-500BK30 model number is decoded
NTN lists 240/500BK30 with a 1:30 tapered bore (K30) and plain outer ring (no D1/W33 groove): 500 mm bore, 720 mm OD, 218 mm width, rated 350 r/min on grease. Reading the full code: the number gives the 500×720 mm envelope, — names the cage/capacity execution, K30 marks the 1:30 tapered bore for sleeve mounting, and plain outer ring (no D1/W33 groove) completes the order number. Suffix reading on 240/500BK30: the bare number is the standard open execution; K30 marks the 1:30 tapered bore of the wide series; 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. The 110.0 mm section height hosts the spherical roller geometry; shaft and housing fillet radii must clear the chamfer table so the 218 mm-wide ring seats fully on both sides. Never mount 240/500BK30 by striking the outer ring through the roller set; drive through ring faces (or the adapter sleeve nut) and support the ring square to avoid brinelling the 720 mm race.
Typical equipment & failure modes
Common applications
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing 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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- water-induced pitting in washdown or outdoor duty without effective external seals
- rolling-contact fatigue after the catalogue L10 life at the actual load
Selection pitfalls — read before you substitute
- At 500 mm bore 240/500BK30 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 218 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- Oil relubrication toward 460 r/min needs drain and level design; flooding the 218 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 240/500BK30 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 218 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The 5300/10900 kN ratings, 640 kN Pu and 290000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/500BK30 (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 240/500BK30?
240/500BK30 is an NTN double-row spherical roller bearing to ISO 15: 500 mm bore, 720 mm OD and 218 mm width (19.685 × 28.346 × 8.583 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 5300 kN, C0 10900 kN, Pu 640 kN, grease limiting speed 350 r/min, oil 460 r/min, mass about 290000 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). 240/500BK30 mounts on a matching adapter or withdrawal sleeve on a plain 500 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 240/500B.
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. 240/500BK30 is the basic execution.
What do D1 and W33 mean on 240/500BK30?
240/500BK30 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 240/500BK30 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 — 5300 kN C / 10900 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.