23976EMKD1 bearing: complete specifications & equivalents

The 23976EMKD1 is a ISO 15 radial bearing sized 380 x 520 x 106 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.

Bearing dimension schematic Front view shows outer diameter D and bore d; side section shows width B. D = 520 mm d = 380 B = 106 mm side section front view
Principal dimensions: bore d 380 mm, outer diameter D 520 mm, width B 106 mm. Schematic, not to scale.

Specification table

ParameterValue
Brand NTN
Bore diameter d 380 mm
Outer diameter D 520 mm
Width B 106 mm
Material GCr15
Seal / shield open
Internal clearance CN
Tolerance class P0
Cage brass, machined (M1)
Basic dynamic load rating C 2340 kN
Basic static load rating C0 4000 kN
Fatigue load limit Pu 205 kN
Limiting speed (mechanical) 710 rpm
Operating temperature -40 to +120 °C
Mass 65900 g
Manufacturer designation NTN 23976EMKD1
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 14.961 in
Outer diameter D 20.472 in
Width B 4.173 in
ISO bore code —
Radial section height (D−d)/2 70 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) 14 of 38
Bore above smallest 23900-series size 220 mm

Cross references & equivalents

Equivalent modelBrandMatch levelNote
23976EMD1 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 23976EMD1 — 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 23976EMKD1 model number is decoded

23976EMKD1 is the EM machined-brass-cage execution of NTN's spherical roller range for a 380 mm shaft — 2340 kN basic dynamic capacity in a 65900 g, open ISO 15 envelope. On the NTN nameplate the suffix cluster after the size reads in order: cage design (EM), bore (K), lubrication feature (D1); 23976EMKD1 is assembled exactly in that order. Suffix reading on 23976EMKD1: EM identifies the high-capacity execution with a one-piece machined brass cage; K marks the 1:12 tapered bore; the * symbol in 2203E marks the ULTAGE new-generation specification (not part of the order code); and D1 provides the outer-ring lubrication feature; quote the full code because each suffix is a distinct article. 380 mm bore is 14.961 in and 520 mm OD is 20.472 in; the ISO 15 envelope swaps between brands, but the 2340/4000 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 380 mm set.

Typical equipment & failure modes

Common applications

  • large SAG/ball-mill trunnion and pinion shafts
  • heavy vibrating screens and grizzly feeders
  • offshore and marine propulsion shaftlines
  • large wind-turbine main-shaft arrangements

Known failure patterns

  • lubricant starvation at the centre rib area when the D1/W33 groove is not connected to a relubrication supply
  • 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
  • hard-particle indentation through the open arrangement in dusty mining duty
  • rolling-contact fatigue after the catalogue L10 life at the actual load

Selection pitfalls — read before you substitute

  • At 380 mm bore 23976EMKD1 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 910 r/min needs drain and level design; flooding the 106 mm cavity churns heat through the heavy roller set and cage despite the higher oil speed figure.
  • 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 380 mm bearing, and drive-up procedures differ.
  • Minimum load must be maintained even at rest under vibration: an unloaded 23976EMKD1 on a stopped screen false-brinells; parking brakes and shaker isolation both matter.
  • The two roller rows must share load equally — a tilted spacer or unequal abutment on the 106 mm-wide ring loads one row only and shows as asymmetric race polish during inspection.
  • The 2340/4000 kN ratings, 205 kN Pu and 65900 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for 23976EMKD1 (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 23976EMKD1?

23976EMKD1 is an NTN double-row spherical roller bearing to ISO 15: 380 mm bore, 520 mm OD and 106 mm width (14.961 × 20.472 × 4.173 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 2340 kN, C0 4000 kN, Pu 205 kN, grease limiting speed 710 r/min, oil 910 r/min, mass about 65900 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. 23976EMKD1 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 23976EMD1.

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. 23976EMKD1 is the EM machined-brass-cage execution, listed with the * ULTAGE new-generation mark.

What do D1 and W33 mean on 23976EMKD1?

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. 23976EMKD1 carries D1; W33 is the equivalent industry-spelled annular-groove-and-holes feature seen on other executions.

How much misalignment and axial load can 23976EMKD1 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 — 2340 kN C / 4000 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.