23084B bearing: complete specifications & equivalents
The 23084B is a ISO 15 radial bearing sized 420 x 620 x 150 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 | 150 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 3450 kN |
| Basic static load rating C0 | 6400 kN |
| Fatigue load limit Pu | 475 kN |
| Limiting speed (mechanical) | 490 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 157000 g |
| Manufacturer designation | NTN 23084B |
| 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 & 23000-series range
| Bore d | 16.535 in |
|---|---|
| Outer diameter D | 24.409 in |
| Width B | 5.906 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 100 mm |
| Smallest bore in 23000-series | 70 mm |
| Largest outer diameter in 23000-series | 1580 mm |
| Width range across 23000-series | 27–345 mm |
| Bore position in 23000-series (smallest first) | 28 of 46 |
| Bore above smallest 23000-series size | 350 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23084BK | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23000-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 23084BK (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 23084B model number is decoded
For heavy radial load with misalignment on a 420 mm shaft, NTN supplies 23084B: sphered outer raceway, two roller rows, pressed-steel cage (standard execution), oil speed 640 r/min. The leading digits are the ISO 15 dimension series (23000 series); the bore code resolves to 420 mm (two-digit code ×5, with the 00–03 exception table), and 620 mm OD / 150 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. Grease/oil ratio: the 490 r/min limiting value is .77 of the 640 r/min oil value; heavy 150 mm-wide cages run hot in churning grease, so quantity and groove supply both matter. Never mount 23084B 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 620 mm race.
Typical equipment & failure modes
Common applications
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
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
- roller-end smearing during skidding starts under light load and high viscosity grease
- rolling-contact fatigue after the catalogue L10 life at the actual load
- 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 23084B 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.
- Oil relubrication toward 640 r/min needs drain and level design; flooding the 150 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- 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 420 mm bearing, and drive-up procedures differ.
- 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.
- 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 420 mm bearing, and drive-up procedures differ.
- The 3450/6400 kN ratings, 475 kN Pu and 157000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23084B (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 23084B?
23084B is an NTN double-row spherical roller bearing to ISO 15: 420 mm bore, 620 mm OD and 150 mm width (16.535 × 24.409 × 5.906 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 3450 kN, C0 6400 kN, Pu 475 kN, grease limiting speed 490 r/min, oil 640 r/min, mass about 157000 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?
23084B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 23084BK (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. 23084B is the basic execution.
What do D1 and W33 mean on 23084B?
23084B 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 23084B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 3450 kN C / 6400 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.