23284B bearing: complete specifications & equivalents
The 23284B is a ISO 15 radial bearing sized 420 x 760 x 272 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 | 760 mm |
| Width B | 272 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 7300 kN |
| Basic static load rating C0 | 12000 kN |
| Fatigue load limit Pu | 820 kN |
| Limiting speed (mechanical) | 380 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 544000 g |
| Manufacturer designation | NTN 23284B |
| 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 & 23200-series range
| Bore d | 16.535 in |
|---|---|
| Outer diameter D | 29.921 in |
| Width B | 10.709 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 170 mm |
| Smallest bore in 23200-series | 90 mm |
| Largest outer diameter in 23200-series | 1360 mm |
| Width range across 23200-series | 52.4–475 mm |
| Bore position in 23200-series (smallest first) | 23 of 34 |
| Bore above smallest 23200-series size | 330 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23284BK | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23200-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 23284BK (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 23284B model number is decoded
23284B is an NTN double-row spherical roller bearing: two rows of symmetric rollers on a sphered outer raceway, 420×760×272 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 (cylindrical), lubrication feature (none); 23284B is assembled exactly in that order. The sphered outer raceway lets the inner-ring assembly pivot, accommodating shaft deflection and housing misalignment (around 1–2° for this class; use the 2203E value for the exact series) without edge loading the rollers. Speed planning: 380 r/min grease limiting speed is the cage/kinematic ceiling and 490 r/min is the oil-lubricated value for the 420 mm bore; vibrating screens rarely approach either and are load/cage limited instead. After mounting on a tapered seat, lock the nut and re-check clearance after a short running-in period, because sleeve seating and ring lift-off can change the residual clearance of the 420 mm set.
Typical equipment & failure modes
Common applications
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
Known failure patterns
- lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
- cage damage when a mounting force is applied through the roller set instead of the ring face
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- 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 420 mm bore 23284B 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.
- Do not confuse EA and EM at the same number: 23284B carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 420×760 mm envelope is identical.
- Oil relubrication toward 490 r/min needs drain and level design; flooding the 272 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Never substitute 23284B by envelope alone: the 12000 kN C0 and 820 kN Pu are specific to the NTN basic execution, and vibrating duty depends heavily on cage identity.
- Minimum load must be maintained even at rest under vibration: an unloaded 23284B on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The 7300/12000 kN ratings, 820 kN Pu and 544000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23284B (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 23284B?
23284B is an NTN double-row spherical roller bearing to ISO 15: 420 mm bore, 760 mm OD and 272 mm width (16.535 × 29.921 × 10.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 7300 kN, C0 12000 kN, Pu 820 kN, grease limiting speed 380 r/min, oil 490 r/min, mass about 544000 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?
23284B has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 23284BK (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. 23284B is the basic execution.
What do D1 and W33 mean on 23284B?
23284B 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 23284B take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23200 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 7300 kN C / 12000 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.