24068EMK30D1 bearing: complete specifications & equivalents
The 24068EMK30D1 is a ISO 15 radial bearing sized 340 x 520 x 180 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 340 mm |
| Outer diameter D | 520 mm |
| Width B | 180 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 3910 kN |
| Basic static load rating C0 | 6510 kN |
| Fatigue load limit Pu | 206 kN |
| Limiting speed (mechanical) | 670 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 137000 g |
| Manufacturer designation | NTN 24068EMK30D1 |
| 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 & 24000-series range
| Bore d | 13.386 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 7.087 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 90 mm |
| Smallest bore in 24000-series | 65 mm |
| Largest outer diameter in 24000-series | 1580 mm |
| Width range across 24000-series | 35–462 mm |
| Bore position in 24000-series (smallest first) | 20 of 42 |
| Bore above smallest 24000-series size | 275 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 24068EMD1 | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same NTN 24000-series envelope, cage and ratings; this is the tapered-bore execution (K30, 1:30) of the cylindrical-bore 24068EMD1 — 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 24068EMK30D1 model number is decoded
24068EMK30D1 is an NTN double-row spherical roller bearing: two rows of symmetric rollers on a sphered outer raceway, 340×520×180 mm to ISO 15, with one-piece machined brass cage (EM high-capacity design). Numbering ties 24068EMK30D1 to its envelope and execution: same-number EA versus EM or plain variants share the 340 mm bore but differ in cage and sometimes mass, so they are quoted as separate articles. The D1 outer-ring annular oil groove with holes 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. Pu 206 kN against C0 6510 kN anchors the contamination derating; for dirty mining duty the adjusted life of 24068EMK30D1 moves with cleanliness far more than with small C variations. 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
- raceway spalling at the roller ends when misalignment or deflection concentrates the line contact
- cage damage when a mounting force is applied through the roller set instead of the ring face
- roller-end smearing during skidding starts under light load and high viscosity grease
- brinelling from static overload or a hammer blow during sleeve mounting
- false brinelling on stopped machines exposed to screen or crusher vibration
Selection pitfalls — read before you substitute
- At 340 mm bore 24068EMK30D1 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.
- Self-aligning does not mean unlimited misalignment: beyond the catalogue angle the outer ring's spherical travel is exhausted and the 3910 kN rating no longer applies.
- Never substitute 24068EMK30D1 by envelope alone: the 6510 kN C0 and 206 kN Pu are specific to the NTN EM machined-brass-cage execution, and vibrating duty depends heavily on cage identity.
- The D1/W33 groove only helps if the housing has a matching grease passage; mounting a D1 24068EMK30D1 in a solid block with no port wastes the feature and leaves the centre rows under-lubricated.
- 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 340 mm bearing, and drive-up procedures differ.
- The 3910/6510 kN ratings, 206 kN Pu and 137000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 24068EMK30D1 (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 24068EMK30D1?
24068EMK30D1 is an NTN double-row spherical roller bearing to ISO 15: 340 mm bore, 520 mm OD and 180 mm width (13.386 × 20.472 × 7.087 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 3910 kN, C0 6510 kN, Pu 206 kN, grease limiting speed 670 r/min, oil 860 r/min, mass about 137000 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 24000 series). 24068EMK30D1 mounts on a matching adapter or withdrawal sleeve on a plain 340 mm shaft and is driven up to a measured radial clearance; the cylindrical-bore counterpart is 24068EMD1.
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. 24068EMK30D1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 24068EMK30D1?
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. 24068EMK30D1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 24068EMK30D1 take?
The sphered outer raceway compensates static and dynamic misalignment in the order of 1–2° (verify the exact 2203E figure for the 24000 series); beyond that, load concentrates on one roller row. Load is predominantly radial with a moderate axial share in either direction — 3910 kN C / 6510 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.