240-500B bearing: complete specifications & equivalents
The 240-500B 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 | 295000 g |
| Manufacturer designation | NTN 240/500B |
| 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 |
|---|---|---|---|
| 240-500BK30 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 240-500BK30 (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 240-500B model number is decoded
NTN lists 240/500B with a cylindrical bore and plain outer ring (no D1/W33 groove): 500 mm bore, 720 mm OD, 218 mm width, rated 350 r/min on grease. The leading digits are the ISO 15 dimension series (24000 series); the bore code resolves to 500 mm (two-digit code ×5, with the 00–03 exception table), and 720 mm OD / 218 mm width follow the general plan. Open by design, 240/500B requires application seals and a grease or oil system; NTN vibrating-duty executions of this envelope are selected with cage and clearance choices that are separate order codes. Grease/oil ratio: the 350 r/min limiting value is .76 of the 460 r/min oil value; heavy 218 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Supply grease through the outer-ring feature during commissioning and at the calculated interval, rotating the 500 mm bore assembly by hand to distribute it across both rows.
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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- false brinelling on stopped machines exposed to screen or crusher vibration
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 500 mm bore 240/500B 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 500 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- 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 D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 240/500B in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 5300 kN rating no longer applies.
- The 5300/10900 kN ratings, 640 kN Pu and 295000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 240/500B (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 240/500B?
240/500B 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 295000 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?
240/500B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 240/500BK30 (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. 240/500B is the basic execution.
What do D1 and W33 mean on 240/500B?
240/500B 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 240/500B 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.