24124EMK30D1 bearing: complete specifications & equivalents
The 24124EMK30D1 is a ISO 15 radial bearing sized 120 x 200 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 200 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 756 kN |
| Basic static load rating C0 | 991 kN |
| Fatigue load limit Pu | 41.3 kN |
| Limiting speed (mechanical) | 1900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 9870 g |
| Manufacturer designation | NTN 24124EMK30D1 |
| 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 & 24100-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 7.874 in |
| Width B | 3.15 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 24100-series | 100 mm |
| Largest outer diameter in 24100-series | 1150 mm |
| Width range across 24100-series | 65–438 mm |
| Bore position in 24100-series (smallest first) | 3 of 32 |
| Bore above smallest 24100-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 24124EMD1 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24100-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 24124EMD1 — 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 24124EMK30D1 model number is decoded
24124EMK30D1 belongs to the 24100 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. On the NTN nameplate the suffix cluster after the size reads in order: cage design (EM), bore (K30), lubrication feature (D1); 24124EMK30D1 is assembled exactly in that order. Pu 41.3 kN is the catalogue fatigue load limit for 24124EMK30D1, used in the adjusted-life equation at contaminated or partial-film conditions typical of mining and vibrating duty. 120 mm bore is 4.724 in and 200 mm OD is 7.874 in; the ISO 15 envelope swaps between brands, but the 756/991 kN ratings and cage design are NTN 2203E values. 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 120 mm set.
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
- machined EM cage wear from inadequate oil film at the cage-guiding surfaces
- roller-end smearing during skidding starts under light load and high viscosity grease
- 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 120 mm bore 24124EMK30D1 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.
- Open spherical rollers swallow dust in mining duty; specify labyrinth or taconite seals externally, or the 1,900 r/min grease rating is lost to abrasive wear long before fatigue.
- Minimum load must be maintained even at rest under vibration: an unloaded 24124EMK30D1 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
- Oil relubrication toward 2,500 r/min needs drain and level design; flooding the 80 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a D1 24124EMK30D1 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- The 756/991 kN ratings, 41.3 kN Pu and 9870 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 24124EMK30D1 (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 24124EMK30D1?
24124EMK30D1 is an NTN double-row spherical roller bearing to ISO 15: 120 mm bore, 200 mm OD and 80 mm width (4.724 × 7.874 × 3.15 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 756 kN, C0 991 kN, Pu 41.3 kN, grease limiting speed 1,900 r/min, oil 2,500 r/min, mass about 9870 g. It is open, with one-piece machined brass cage (EM high-capacity design) and a 1:30 tapered bore.
What is the difference between the K/K30 tapered bore and the cylindrical bore versions?
K30 denotes a 1:30 tapered bore (the wide 24100 series). 24124EMK30D1 mounts on a matching adapter or withdrawal sleeve on a plain 120 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 24124EMD1.
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. 24124EMK30D1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 24124EMK30D1?
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. 24124EMK30D1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 24124EMK30D1 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24100 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 756 kN C / 991 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.