23944EMKD1 bearing: complete specifications & equivalents
The 23944EMKD1 is a ISO 15 radial bearing sized 220 x 300 x 60 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 220 mm |
| Outer diameter D | 300 mm |
| Width B | 60 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 789 kN |
| Basic static load rating C0 | 1260 kN |
| Fatigue load limit Pu | 79.4 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12100 g |
| Manufacturer designation | NTN 23944EMKD1 |
| 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 | 8.661 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.362 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 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) | 6 of 38 |
| Bore above smallest 23900-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23944EMD1 | 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 23944EMD1 — 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 23944EMKD1 model number is decoded
For heavy radial load with misalignment on a 220 mm shaft, NTN supplies 23944EMKD1: sphered outer raceway, two roller rows, one-piece machined brass cage (EM high-capacity design), oil speed 1,700 r/min. Reading the full code: the number gives the 220×300 mm envelope, EM names the cage/capacity execution, K marks the 1:12 tapered bore for adapter/withdrawal-sleeve mounting, and D1 outer-ring annular oil groove with holes completes the order number. At 789 kN C and 12100 g mass the 23900 series part is built for shock and vibration; the 60 mm-wide ring needs square abutments to keep both rows equally loaded. Speed planning: 1,400 r/min grease limiting speed is the cage/kinematic ceiling and 1,700 r/min is the oil-lubricated value for the 220 mm bore; vibrating screens rarely approach either and are load/cage limited instead. Never mount 23944EMKD1 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 300 mm race.
Typical equipment & failure modes
Common applications
- offshore and marine propulsion shaftlines
- large wind-turbine main-shaft arrangements
- steel-mill and heavy crusher main shafts
- mining shovel and dragline swing shafts
Known failure patterns
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- pressed EA cage fatigue under sustained vibration when minimum load is not maintained
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- rolling-contact fatigue after the catalogue L10 life at the actual load
- false brinelling on stopped machines exposed to screen or crusher vibration
Selection pitfalls — read before you substitute
- At 220 mm bore 23944EMKD1 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 two roller rows must share load equally — a tilted spacer or unequal abutment on the 60 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 220 mm bearing, and drive-up procedures differ.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 1,400 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 1,400 r/min grease rating is lost to abrasive wear long before fatigue.
- The 789/1260 kN ratings, 79.4 kN Pu and 12100 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23944EMKD1 (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 23944EMKD1?
23944EMKD1 is an NTN double-row spherical roller bearing to ISO 15: 220 mm bore, 300 mm OD and 60 mm width (8.661 × 11.811 × 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 789 kN, C0 1260 kN, Pu 79.4 kN, grease limiting speed 1,400 r/min, oil 1,700 r/min, mass about 12100 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. 23944EMKD1 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 23944EMD1.
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. 23944EMKD1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 23944EMKD1?
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. 23944EMKD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 23944EMKD1 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 — 789 kN C / 1260 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.