23088BK bearing: complete specifications & equivalents
The 23088BK is a ISO 15 radial bearing sized 440 x 650 x 157 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 | 157 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 3650 kN |
| Basic static load rating C0 | 6850 kN |
| Fatigue load limit Pu | 530 kN |
| Limiting speed (mechanical) | 470 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 175000 g |
| Manufacturer designation | NTN 23088BK |
| 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 | 17.323 in |
|---|---|
| Outer diameter D | 25.591 in |
| Width B | 6.181 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 105 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) | 29 of 46 |
| Bore above smallest 23000-series size | 370 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23088B | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23000-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 23088B — 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 23088BK model number is decoded
NTN lists 23088BK with a 1:12 tapered bore (K) and plain outer ring (no D1/W33 groove): 440 mm bore, 650 mm OD, 157 mm width, rated 470 r/min on grease. Reading the full code: the number gives the 440×650 mm envelope, — names the cage/capacity execution, K marks the 1:12 tapered bore for adapter/withdrawal-sleeve mounting, and plain outer ring (no D1/W33 groove) completes the order number. 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. Pu 530 kN against C0 6850 kN anchors the contamination derating; for dirty mining duty the adjusted life of 23088BK moves with cleanliness far more than with small C variations. Never mount 23088BK 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 650 mm race.
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
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- 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
- brinelling from static overload or a hammer blow during sleeve mounting
Selection pitfalls — read before you substitute
- At 440 mm bore 23088BK 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 D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 23088BK in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Do not confuse EA and EM at the same number: 23088BK carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 440×650 mm envelope is identical.
- Do not confuse EA and EM at the same number: 23088BK carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 440×650 mm envelope is identical.
- Minimum load must be maintained even at rest under vibration: an unloaded 23088BK on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The 3650/6850 kN ratings, 530 kN Pu and 175000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23088BK (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 23088BK?
23088BK is an NTN double-row spherical roller bearing to ISO 15: 440 mm bore, 650 mm OD and 157 mm width (17.323 × 25.591 × 6.181 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 3650 kN, C0 6850 kN, Pu 530 kN, grease limiting speed 470 r/min, oil 610 r/min, mass about 175000 g. It is open, with pressed-steel cage (standard execution) and a 1:12 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K denotes a 1:12 tapered bore. 23088BK mounts on an adapter sleeve (or tapered shaft seat) and is driven up to the specified residual clearance; its cylindrical-bore counterpart in the same envelope and ratings is 23088B.
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. 23088BK is the basic execution.
What do D1 and W33 mean on 23088BK?
23088BK 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 23088BK 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 — 3650 kN C / 6850 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.