32030XU bearing: complete specifications & equivalents
The 32030XU is a ISO 355 radial bearing sized 150 x 225 x 48 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 150 mm |
| Outer diameter D | 225 mm |
| Width B | 48 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 410 kN |
| Basic static load rating C0 | 655 kN |
| Fatigue load limit Pu | 66 kN |
| Limiting speed (mechanical) | 1400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6450 g |
| Manufacturer designation | NTN 32030XU |
| Standard | ISO 355 |
| 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 & 32000-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 8.858 in |
| Width B | 1.89 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 37.5 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 650 mm |
| Width range across 32000-series | 15–130 mm |
| Bore position in 32000-series (smallest first) | 26 of 43 |
| Bore above smallest 32000-series size | 130 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32030XU | 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 32030XU model number is decoded
32030XU is the NTN 4T catalogue entry for a 150×225×48 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32030XU resolves to 150 mm bore; the NTN factory mark 4T is stamped on cone and cup but is a brand mark, not a size code, so the catalogue sku is printed without it. NTN adjusts these bearings by cup or cone position rather than shipping a preloaded set; the mounting drawing must state end play or preload for 32030XU, since running clearance is set during assembly. The two speed columns differ by a factor of .74 (grease/limiting 1,400 vs oil 1,900 r/min); heat generation at the cone rib decides which lubrication a real 32030XU arrangement can sustain. With a rotating shaft a m6/n6 shaft seat and a press-fit cup are typical catalogue practice for 32030XU; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- offshore crane and drawworks drums
- heavy haul railway traction gearboxes
- large marine propulsion reduction gears
- cement-plant kiln and mill drive trains
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- water-induced pitting when the open bearing is exposed to washdown without external seals
Selection pitfalls — read before you substitute
- At 150 mm bore the 32030XU set is adjusted with hydraulic nuts on large mill and wind positions; follow the drive-up angle/end-play procedure, because manual torque methods cannot control preload at the 410 kN C level.
- The thin 48 mm section of 32030XU is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 150 mm bore smears the roller ends against the rib.
- Minimum load matters at high speed: an unloaded 32030XU at a large fraction of 1,400 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 37.5 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32030XU or the ring will bottom out on the radius instead of the shoulder face.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 150 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 410/655 kN ratings and 66 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32030XU (ISO 355 4EC); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 32030XU?
32030XU is a metric 4T tapered roller bearing to ISO 355: 150 mm bore, 225 mm outside diameter and 48 mm assembled width T (5.906 × 8.858 × 1.89 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 410 kN, C0 655 kN, Pu 66 kN, grease limiting speed 1,400 r/min, oil speed 1,900 r/min, mass about 6450 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32030XU?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (32030XU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32030XU designation encode the 150 mm bore and what is 4EC?
last two digits 30 are the ISO bore code, ×5 = 150 mm (codes 00–03 use the 10/12/15/17 exception table). The 225 mm OD and 48 mm assembled T follow the ISO 355 dimension-series plan. 4EC is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 32030XU list two speeds, 1,400 and 1,900 r/min?
The lower figure, 1,400 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32030XU at 1,900 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32030XU mean?
Suffix reading on 32030XU: XU combines the X ISO boundary section with the U uprated internal design; U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; the suffix is part of the order number and the variants are not interchangeable articles.
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.