24084BK30 bearing: complete specifications & equivalents
The 24084BK30 is a ISO 15 radial bearing sized 420 x 620 x 200 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 420 mm |
| Outer diameter D | 620 mm |
| Width B | 200 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 4300 kN |
| Basic static load rating C0 | 8450 kN |
| Fatigue load limit Pu | 470 kN |
| Limiting speed (mechanical) | 440 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 207000 g |
| Manufacturer designation | NTN 24084BK30 |
| 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 | 16.535 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 7.874 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 100 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) | 24 of 42 |
| Bore above smallest 24000-series size | 355 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 24084B | 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 24084B — 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 24084BK30 model number is decoded
24084BK30 is an NTN double-row spherical roller bearing: two rows of symmetric rollers on a sphered outer raceway, 420×620×200 mm to ISO 15, with pressed-steel cage (standard execution). On the NTN nameplate the suffix cluster after the size reads in order: cage design (—), bore (K30), lubrication feature (none); 24084BK30 is assembled exactly in that order. Suffix reading on 24084BK30: 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. Catalogue mass 207000 g (207.00 kg) for the 420×620×200 mm execution includes the basic cage and both roller rows; shaft and housing shoulders must support that ring squarely. 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
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- cage damage when a mounting force is applied through the roller set instead of the ring face
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- brinelling from static overload or a hammer blow during sleeve mounting
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 420 mm bore 24084BK30 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.
- Minimum load must be maintained even at rest under vibration: an unloaded 24084BK30 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 420 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K30 seats.
- Never substitute 24084BK30 by envelope alone: the 8450 kN C0 and 470 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 200 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- The 4300/8450 kN ratings, 470 kN Pu and 207000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 24084BK30 (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 24084BK30?
24084BK30 is an NTN double-row spherical roller bearing to ISO 15: 420 mm bore, 620 mm OD and 200 mm width (16.535 × 24.409 × 7.874 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 4300 kN, C0 8450 kN, Pu 470 kN, grease limiting speed 440 r/min, oil 570 r/min, mass about 207000 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). 24084BK30 mounts on a matching adapter or withdrawal sleeve on a plain 420 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 24084B.
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. 24084BK30 is the basic execution.
What do D1 and W33 mean on 24084BK30?
24084BK30 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 24084BK30 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 — 4300 kN C / 8450 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.