23948EMD1 bearing: complete specifications & equivalents
The 23948EMD1 is a ISO 15 radial bearing sized 240 x 320 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 | 240 mm |
| Outer diameter D | 320 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 | 815 kN |
| Basic static load rating C0 | 1350 kN |
| Fatigue load limit Pu | 87.7 kN |
| Limiting speed (mechanical) | 1300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 13500 g |
| Manufacturer designation | NTN 23948EMD1 |
| 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 | 9.449 in |
|---|---|
| Outer diameter D | 12.598 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) | 7 of 38 |
| Bore above smallest 23900-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23948EMKD1 | 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 23948EMKD1 (K/K30 sleeve or tapered-seat mounting). 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 23948EMD1 model number is decoded
23948EMD1 belongs to the 23900 series of NTN spherical rollers and carries the ＊ ULTAGE new-generation mark in the 2203E table: self-aligning, high radial capacity, moderate axial load in either direction. The leading digits are the ISO 15 dimension series (23900 series); the bore code resolves to 240 mm (two-digit code ×5, with the 00–03 exception table), and 320 mm OD / 60 mm width follow the general plan. Two symmetric roller rows share the load: C 815 kN, C0 1350 kN (C0/C ≈ 1.66), with useful axial capacity in either direction alongside the dominant radial load. With about 3.4 kN of C per millimetre of the 240 mm bore, 23948EMD1 screens interchange candidates quickly — then verify cage (EA/EM), bore (K/K30) and lubrication feature (D1/W33) suffixes. After mounting on a tapered seat, lock the nut and re-check clearance after a short running-in period, because sleeve seating and ring lift-off can change the residual clearance of the 240 mm set.
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
- 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
- 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
- fretting corrosion between adapter sleeve and tapered bore when the drive-up is insufficient
Selection pitfalls — read before you substitute
- At 240 mm bore 23948EMD1 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.
- Minimum load must be maintained even at rest under vibration: an unloaded 23948EMD1 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a D1 23948EMD1 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- Oil relubrication toward 1,600 r/min needs drain and level design; flooding the 60 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- Adapter-sleeve mounting requires the correct sleeve series and locknut for the 240 mm shaft; a sleeve sized to bore alone ignores thread, width and the oil-injection option on large K seats.
- The 815/1350 kN ratings, 87.7 kN Pu and 13500 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23948EMD1 (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 23948EMD1?
23948EMD1 is an NTN double-row spherical roller bearing to ISO 15: 240 mm bore, 320 mm OD and 60 mm width (9.449 × 12.598 × 2.362 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 815 kN, C0 1350 kN, Pu 87.7 kN, grease limiting speed 1,300 r/min, oil 1,600 r/min, mass about 13500 g. It is open, with one-piece machined brass cage (EM high-capacity design).
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
23948EMD1 has a cylindrical bore and mounts directly on a machined shaft seat. Its tapered-bore counterpart is 23948EMKD1 (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. 23948EMD1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 23948EMD1?
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. 23948EMD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 23948EMD1 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 — 815 kN C / 1350 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.