23996K bearing: complete specifications & equivalents
The 23996K 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 | 119000 g |
| Manufacturer designation | NTN 23996K |
| 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 | — |
| 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 |
|---|---|---|---|
| 23996-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 23900-series envelope, cage and ratings; this is the tapered-bore execution (K, 1:12) of the cylindrical-bore 23996-NTN — 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 23996K model number is decoded
23996K is the basic execution of NTN's spherical roller range for a 480 mm shaft — 2590 kN basic dynamic capacity in a 119000 g, open ISO 15 envelope. Digit by digit the code reads as spherical-roller dimension series plus 480 mm bore; the 128 mm width is the wide ISO 15 section, which is why spherical rollers interchange dimensionally but not in cage or rating detail. 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. With about 5.4 kN of C per millimetre of the 480 mm bore, 23996K screens interchange candidates quickly — then verify cage (EA/EM), bore (K/K30) and lubrication feature (D1/W33) suffixes. 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
- 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
- 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
- water-induced pitting in washdown or outdoor duty without effective external seals
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 480 mm bore 23996K 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 23996K in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a grooved 23996K in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The two roller rows must share load equally — a tilted spacer or unequal abutment on the 128 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
- 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 119000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23996K (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 23996K?
23996K 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 119000 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. 23996K 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 23996.
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. 23996K is the basic execution.
What do D1 and W33 mean on 23996K?
23996K 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 23996K 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.