430308DX bearing: complete specifications & equivalents
The 430308DX is a ANSI ABMA 19.2 radial bearing sized 40 x 90 x 56 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 90 mm |
| Width B | 56 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 147 kN |
| Basic static load rating C0 | 171 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1590 g |
| Manufacturer designation | NTN 4T-430308DX |
| Standard | ANSI ABMA 19.2 |
| Catalog version | NTN 2203E 2026-09-25 |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN 2203E 2026-09-25) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN 2203E 2026-09-25); 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 & 4t-430-series range
| Bore d | 1.575 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 2.205 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 4t-430-series | 40 mm |
| Largest outer diameter in 4t-430-series | 870 mm |
| Width range across 4t-430-series | 45–310 mm |
| Bore position in 4t-430-series (smallest first) | 1 of 41 |
| Bore above smallest 4t-430-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 430308DX | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 430308DX model number is decoded
For a 40 mm shaft needing a compact two-direction thrust location, NTN lists 4T-430308DX, a TDO double-row 4T unit of 147 kN C and 171 kN C0 in the light-duty 430-family TDO double-row series. Unlike a pair of single-row bearings, the TDO unit of 4T-430308DX integrates both rows in one article: the 56 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 25.0 mm radial section over the 40 mm bore carries two roller rows across the 56 mm width; abutment shoulders must clear both cone bores and the double-cup OD. TDO construction means the two cone assemblies of 4T-430308DX face away from each other inside one double cup: the load lines diverge outward, giving a wide effective spread and high moment stiffness for the 40 mm shaft. Do not separate the cones from the double cup at inspection unless re-matching is guaranteed — the rows of 4T-430308DX are ground as a unit.
Typical equipment & failure modes
Common applications
- extruder and mixer drive shafts
- construction-equipment swing and pivot shafts
- industrial gearbox shafts in a single locating position
- rolling-mill work-roll and backup auxiliary positions
Known failure patterns
- roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant
- preload loss and hammering noise when the cup clamping loosens and the unit gains axial float
- brinelling of both rows from a mounting blow transmitted through the roller complements
- pressed-steel cage pocket wear from roller skid at light load and high speed
- water-induced pitting when washdown reaches the open unit without external seals
Selection pitfalls — read before you substitute
- Gearbox positions of this 40 mm class rely on the preset clearance of 4T-430308DX; shimming or nut-tightening the unit like a single-row pair overruns the factory setting and runs the rows hot.
- The 430 light plan keeps 4T-430308DX narrower and faster than the 432 heavy execution of the same 40 mm bore; where shock or a high thrust share dominates, verify whether the heavier 432-family row is the intended position.
- The 147 kN C already includes two-row load sharing — do not double it when pairing the unit with a floating bearing in the L10 calculation.
- The 25.0 mm section leaves little room for oversized shaft fillets; follow the 2203E chamfer table for 4T-430308DX or the cones bottom out on the radius.
- Order by the full 430308DX code including suffixes — U, X, DX, E1 and UTG variants share the 40 mm bore but are different articles with different internal geometry.
- The 147/171 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-430308DX; internal geometry legitimately differs between manufacturers, so re-verify ratings, clearance class and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 4T-430308DX?
4T-430308DX is a double-row tapered roller bearing of TDO (back-to-back) construction: 40 mm bore, 90 mm outside diameter and 56 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 147 kN, C0 171 kN (2203E prints a dash for Cu on this size), grease limiting speed 3,200 r/min, oil speed 4,200 r/min, mass about 1.59 kg. It is an open, preset-clearance unit with pressed-steel cages.
What is the difference between the NTN 430 and 432 double-row series at 40 mm bore?
Both are TDO double-row tapered roller units, but 430 is the light plan and 432 the heavy plan: at the same bore the 432 execution is wider and heavier with higher load ratings. 4T-430308DX belongs to the light-duty 430-family TDO double-row series. Large sizes continue the plans as 4130/4131/4230/4231 (430 family) and 3230/3231 (432 family).
Can the internal clearance of 4T-430308DX be adjusted at mounting?
No. The TDO unit — two cone assemblies against one double cup — is ground and set by NTN at the factory, and the 56 mm overall width is the finished dimension. Mounting sets no end play: seat the unit square, clamp the cup uniformly and verify free rotation. Field re-adjustment overloads one row.
What do the suffix letters on 430308DX mean?
Suffix reading on 430308DX: X marks the boundary-dimension revision of the base number (D and width differ from the plain number of the same bore); suffixed variants are separate order numbers and are not interchangeable articles.
Why does 4T-430308DX list two speeds, 3,200 and 4,200 r/min?
The lower figure, 3,200 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-430308DX at 4,200 r/min because oil removes heat from both roller rows better — the housing feed must reach both rows through the double cup.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN 2203E 2026-09-25 on 2026-10-01. Read our editorial & correction policy.