23956EMKD1 bearing: complete specifications & equivalents
The 23956EMKD1 is a ISO 15 radial bearing sized 280 x 380 x 75 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 280 mm |
| Outer diameter D | 380 mm |
| Width B | 75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 1180 kN |
| Basic static load rating C0 | 2050 kN |
| Fatigue load limit Pu | 115 kN |
| Limiting speed (mechanical) | 1000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 24400 g |
| Manufacturer designation | NTN 23956EMKD1 |
| 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 | 11.024 in |
|---|---|
| Outer diameter D | 14.961 in |
| Width B | 2.953 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 50 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) | 9 of 38 |
| Bore above smallest 23900-series size | 120 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23956EMD1 | 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 23956EMD1 — 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 23956EMKD1 model number is decoded
23956EMKD1 is the EM machined-brass-cage execution of NTN's spherical roller range for a 280 mm shaft — 1180 kN basic dynamic capacity in a 24400 g, open ISO 15 envelope. Numbering ties 23956EMKD1 to its envelope and execution: same-number EA versus EM or plain variants share the 280 mm bore but differ in cage and sometimes mass, so they are quoted as separate articles. At 1180 kN C and 24400 g mass the 23900 series part is built for shock and vibration; the 75 mm-wide ring needs square abutments to keep both rows equally loaded. Speed planning: 1,000 r/min grease limiting speed is the cage/kinematic ceiling and 1,300 r/min is the oil-lubricated value for the 280 mm bore; vibrating screens rarely approach either and are load/cage limited instead. Supply grease through the D1 feature during commissioning and at the calculated interval, rotating the 280 mm bore assembly by hand to distribute it across both rows.
Typical equipment & failure modes
Common applications
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
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
- micro-pitting when the EHL film is thinner than the raceway composite roughness
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
- asymmetric wear on the two roller rows from sustained angular misalignment beyond the self-aligning range
Selection pitfalls — read before you substitute
- At 280 mm bore 23956EMKD1 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.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 280 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K 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 280 mm bearing, and drive-up procedures differ.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 1,000 r/min grease rating is lost to abrasive wear long before fatigue.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 1,000 r/min grease rating is lost to abrasive wear long before fatigue.
- The 1180/2050 kN ratings, 115 kN Pu and 24400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23956EMKD1 (EM machined-brass-cage/D1); 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 23956EMKD1?
23956EMKD1 is an NTN double-row spherical roller bearing to ISO 15: 280 mm bore, 380 mm OD and 75 mm width (11.024 × 14.961 × 2.953 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 1180 kN, C0 2050 kN, Pu 115 kN, grease limiting speed 1,000 r/min, oil 1,300 r/min, mass about 24400 g. It is open, with one-piece machined brass cage (EM high-capacity design) 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. 23956EMKD1 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 23956EMD1.
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. 23956EMKD1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 23956EMKD1?
D1 is NTN's outer-ring lubrication feature: an annular groove with oil holes around the outer ring, aligned with a housing grease port so lubricant reaches both roller rows directly. 23956EMKD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 23956EMKD1 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 — 1180 kN C / 2050 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.