23996-NTN bearing: complete specifications & equivalents
The 23996-NTN is a ISO 15 radial bearing sized 480 x 650 x 128 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 480 mm |
| Outer diameter D | 650 mm |
| Width B | 128 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 2590 kN |
| Basic static load rating C0 | 5500 kN |
| Fatigue load limit Pu | 365 kN |
| Limiting speed (mechanical) | 450 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 123000 g |
| Manufacturer designation | NTN 23996 |
| 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 & 23900-series range
| Bore d | 18.898 in |
|---|---|
| Outer diameter D | 25.591 in |
| Width B | 5.039 in |
| ISO bore code | 96 |
| Radial section height (D−d)/2 | 85 mm |
| Smallest bore in 23900-series | 160 mm |
| Largest outer diameter in 23900-series | 1820 mm |
| Width range across 23900-series | 45–315 mm |
| Bore position in 23900-series (smallest first) | 19 of 38 |
| Bore above smallest 23900-series size | 320 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23996K | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the cylindrical-bore execution of the tapered-bore 23996K (K/K30 sleeve or tapered-seat mounting). Verify shaft arrangement. |
| 23996 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 480×650×128 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 23996-CAK-W33 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 480×650×128 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 23996-NTN model number is decoded
The NTN order number 23996 identifies a 480×650×128 mm (18.898 × 25.591 × 5.039 in) spherical roller bearing, cylindrical bore, to the ISO 15 boundary plan. The leading digits are the ISO 15 dimension series (23900 series); the bore code resolves to 480 mm (two-digit code ×5, with the 00–03 exception table), and 650 mm OD / 128 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. Equivalent-load planning keeps a radial plus moderate axial combination on 23996; if the axial component dominates, pair with a thrust bearing rather than running one roller row unloaded. Fillet radii on shaft and housing must clear the ring chamfers of the 128 mm-wide set; use the NTN shoulder/withdrawal-groove table rather than copying a ball-bearing layout.
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
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
Selection pitfalls — read before you substitute
- At 480 mm bore 23996 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 23996 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 450 r/min grease rating is lost to abrasive wear long before fatigue.
- Do not confuse EA and EM at the same number: 23996 carries basic; swapping to the other cage execution changes mass, speed behaviour and sometimes suitability for vibration, even though the 480×650 mm envelope is identical.
- 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 480 mm bearing, and drive-up procedures differ.
- The 2590/5500 kN ratings, 365 kN Pu and 123000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23996 (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 23996?
23996 is an NTN double-row spherical roller bearing to ISO 15: 480 mm bore, 650 mm OD and 128 mm width (18.898 × 25.591 × 5.039 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 2590 kN, C0 5500 kN, Pu 365 kN, grease limiting speed 450 r/min, oil 590 r/min, mass about 123000 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?
23996 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 23996K (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. 23996 is the basic execution.
What do D1 and W33 mean on 23996?
23996 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 23996 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 23900 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 2590 kN C / 5500 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.