323126 bearing: complete specifications & equivalents
The 323126 is a ANSI ABMA 19.2 radial bearing sized 130 x 210 x 64 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 130 mm |
| Outer diameter D | 210 mm |
| Width B | 64 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 455 kN |
| Basic static load rating C0 | 675 kN |
| Fatigue load limit Pu | 70.5 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8380 g |
| Manufacturer designation | NTN 4T-323126 |
| 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-432-series range
| Bore d | 5.118 in |
|---|---|
| Outer diameter D | 8.268 in |
| Width B | 2.52 in |
| ISO bore code | 26 |
| Radial section height (D−d)/2 | 40 mm |
| Smallest bore in 4t-432-series | 40 mm |
| Largest outer diameter in 4t-432-series | 790 mm |
| Width range across 4t-432-series | 46–266 mm |
| Bore position in 4t-432-series (smallest first) | 17 of 39 |
| Bore above smallest 4t-432-series size | 90 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 323126 | 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 323126 model number is decoded
4T-323126 is an NTN double-row tapered roller bearing of TDO (back-to-back) construction: two cone assemblies against one double cup, supplied as a preset unit of 130×210×64 mm. Unlike a pair of single-row bearings, the TDO unit of 4T-323126 integrates both rows in one article: the 64 mm overall width and the internal clearance are ground and set by NTN, so there is no field adjustment dimension. The 3.5 kN of dynamic capacity per millimetre of bore summarises the 455 kN rating over the 130 mm bore — compare substitution candidates on this ratio and on the 64 mm width. TDO construction means the two cone assemblies of 4T-323126 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 130 mm shaft. At 455 kN C the unit offers about 3.5 kN per millimetre of the 130 mm bore — heavy-section TDO rows of this class run warm, so confirm oil availability before working near 1,800 r/min.
Typical equipment & failure modes
Common applications
- large shredder and recycler main shafts
- power-plant mill and fan shafts
- rolling-mill roll-neck and pinion-stand positions
- mine hoist and dragline drum shafts
Known failure patterns
- roller large-end smearing against the cone ribs when one row of the unit runs starved of lubricant
- one-row flaking when a bent shaft concentrates the combined load on a single row of the pair
- overheated running after a field attempt to "tighten up" the factory-set internal clearance
- cage damage when the unit is lifted by one cone instead of the double cup during fitting
- water-induced pitting when washdown reaches the open unit without external seals
Selection pitfalls — read before you substitute
- At 130 mm bore the 4T-323126 unit needs hydraulic or crane-assisted fitting and a verified oil supply; manual methods cannot control seating at the 455 kN C level.
- The 432 heavy plan gives 4T-323126 its 64 mm width and 455 kN rating at the 130 mm bore; do not downgrade to a 430-family unit of the same bore without re-checking C, C0 and the 70.5 kN Cu.
- At inspection do not mix the cone assemblies of 4T-323126 with another unit; rows are ground together and re-matching is not guaranteed in the field.
- Grease packs must leave free volume across the 64 mm width; over-greasing a unit churning near the 1,800 r/min oil-band speed raises temperature and expels the grease.
- Clamping the double cup with a cocked end cover pinches one row: tighten the 210 mm OD clamping uniformly around the circumference.
- The 455/675 kN ratings and 70.5 kN Cu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-323126; 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-323126?
4T-323126 is a double-row tapered roller bearing of TDO (back-to-back) construction: 130 mm bore, 210 mm outside diameter and 64 mm overall width. From NTN Ball and Roller Bearings CAT.No.2203E: C 455 kN, C0 675 kN, Cu 70.5 kN, grease limiting speed 1,400 r/min, oil speed 1,800 r/min, mass about 8.38 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 130 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-323126 belongs to the heavy-duty 432-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-323126 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 64 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 323126 mean?
With no letter suffix, 323126 is the basic open double-row execution: steel cages, factory-set internal clearance, no feature suffix in the order code.
Why does 4T-323126 list two speeds, 1,400 and 1,800 r/min?
The lower figure, 1,400 r/min, is the grease-lubricated limiting speed for the two rows and their cages. With oil lubrication NTN rates 4T-323126 at 1,800 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.