24088BK30 bearing: complete specifications & equivalents
The 24088BK30 is a ISO 15 radial bearing sized 440 x 650 x 212 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 440 mm |
| Outer diameter D | 650 mm |
| Width B | 212 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 4800 kN |
| Basic static load rating C0 | 9450 kN |
| Fatigue load limit Pu | 530 kN |
| Limiting speed (mechanical) | 420 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 241000 g |
| Manufacturer designation | NTN 24088BK30 |
| 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 | 17.323 in |
|---|---|
| Outer diameter D | 25.591 in |
| Width B | 8.346 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 105 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) | 25 of 42 |
| Bore above smallest 24000-series size | 375 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 24088B | 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 24088B — 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 24088BK30 model number is decoded
NTN lists 24088BK30 with a 1:30 tapered bore (K30) and plain outer ring (no D1/W33 groove): 440 mm bore, 650 mm OD, 212 mm width, rated 420 r/min on grease. On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (K30), lubrication feature (none); 24088BK30 is assembled exactly in that order. Two symmetric roller rows share the load: C 4800 kN, C0 9450 kN (C0/C ≈ 1.97), with useful axial capacity in either direction alongside the dominant radial load. Speed planning: 420 r/min grease limiting speed is the cage/kinematic ceiling and 540 r/min is the oil-lubricated value for the 440 mm bore; vibrating screens rarely approach either and are load/cage limited instead. On vibrating-duty shafts verify the radial clearance class and cage choice at order time; the open 24088BK30 leaves sealing and the C3/C4 clearance decision to the application drawing.
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
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- hard-particle indentation through the open arrangement in dusty mining duty
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
Selection pitfalls — read before you substitute
- At 440 mm bore 24088BK30 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 1:30 tapered bore is the only difference from the cylindrical-bore 24088B: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 420 r/min grease rating is lost to abrasive wear long before fatigue.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 4800 kN rating no longer applies.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 440 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- The 4800/9450 kN ratings, 530 kN Pu and 241000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 24088BK30 (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 24088BK30?
24088BK30 is an NTN double-row spherical roller bearing to ISO 15: 440 mm bore, 650 mm OD and 212 mm width (17.323 × 25.591 × 8.346 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 4800 kN, C0 9450 kN, Pu 530 kN, grease limiting speed 420 r/min, oil 540 r/min, mass about 241000 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). 24088BK30 mounts on a matching adapter or withdrawal sleeve on a plain 440 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 24088B.
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. 24088BK30 is the basic execution.
What do D1 and W33 mean on 24088BK30?
24088BK30 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 24088BK30 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 — 4800 kN C / 9450 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.