23938EMKD1 bearing: complete specifications & equivalents
The 23938EMKD1 is a ISO 15 radial bearing sized 190 x 260 x 52 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 190 mm |
| Outer diameter D | 260 mm |
| Width B | 52 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 603 kN |
| Basic static load rating C0 | 935 kN |
| Fatigue load limit Pu | 62.8 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7960 g |
| Manufacturer designation | NTN 23938EMKD1 |
| 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 | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 2.047 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 35 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) | 4 of 38 |
| Bore above smallest 23900-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23938EMD1 | 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 23938EMD1 — 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 23938EMKD1 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 23938EMKD1 denotes the 190 mm bore spherical roller bearing (603 kN C / 935 kN C0) in the 23900 series, the self-aligning choice for heavy combined load. Numbering ties 23938EMKD1 to its envelope and execution: same-number EA versus EM or plain variants share the 190 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. Catalogue mass 7960 g (7.96 kg) for the 190×260×52 mm execution includes the EM machined-brass-cage cage and both roller rows; shaft and housing shoulders must support that ring squarely. Supply grease through the D1 feature during commissioning and at the calculated interval, rotating the 190 mm bore assembly by hand to distribute it across both rows.
Typical equipment & failure modes
Common applications
- mining shovel and dragline swing shafts
- cement-rotary-kiln support and trunnion rolls
- large SAG/ball-mill trunnion and pinion shafts
- heavy vibrating screens and grizzly feeders
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
- sliding wear and heat when relubrication intervals ignore the groove (D1/W33) supply path
- brinelling from static overload or a hammer blow during sleeve mounting
- water-induced pitting in washdown or outdoor duty without effective external seals
Selection pitfalls — read before you substitute
- At 190 mm bore 23938EMKD1 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.
- Oil relubrication toward 2,000 r/min needs drain and level design; flooding the 52 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
- The 1:12 tapered bore is the only difference from the cylindrical-bore 23938EMD1: envelopes and ratings match, but drive-up tooling, sleeve and seat do not — never mix the two mounting methods.
- 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 190 mm bearing, and drive-up procedures differ.
- 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 190 mm bearing, and drive-up procedures differ.
- The 603/935 kN ratings, 62.8 kN Pu and 7960 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23938EMKD1 (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 23938EMKD1?
23938EMKD1 is an NTN double-row spherical roller bearing to ISO 15: 190 mm bore, 260 mm OD and 52 mm width (7.48 × 10.236 × 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 603 kN, C0 935 kN, Pu 62.8 kN, grease limiting speed 1,600 r/min, oil 2,000 r/min, mass about 7960 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. 23938EMKD1 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 23938EMD1.
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. 23938EMKD1 is the EM machined-brass-cage execution, listed with the ＊ ULTAGE new-generation mark.
What do D1 and W33 mean on 23938EMKD1?
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. 23938EMKD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.
How much misalignment and axial load can 23938EMKD1 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 — 603 kN C / 935 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.