30319DU bearing: complete specifications & equivalents
The 30319DU is a ISO 355 radial bearing sized 95 x 200 x 49.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 95 mm |
| Outer diameter D | 200 mm |
| Width B | 49.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 330 kN |
| Basic static load rating C0 | 355 kN |
| Fatigue load limit Pu | 38.5 kN |
| Limiting speed (mechanical) | 1700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6350 g |
| Manufacturer designation | NTN 30319DU |
| 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 & 30300-series range
| Bore d | 3.74 in |
|---|---|
| Outer diameter D | 7.874 in |
| Width B | 1.949 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 52.5 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 18 of 32 |
| Bore above smallest 30300-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30319DU | 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 30319DU model number is decoded
30319DU is the NTN 4T catalogue entry for a 95×200×49.5 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. The last two digits 19 are the ISO bore code, ×5 = 95 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 49.5 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. The printed contact-angle geometry gives the large-OD 30300 family with the steeper contact angle its characteristic load split — at 330/355 kN (C/C0) the static rating is about 1.08× C, typical of tapered bearings proportioned for heavy combined duty. Selection: C 330 kN against C0 355 kN gives a C0/C ratio of 1.08 for the 95 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Mount the 95 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 30319DU.
Typical equipment & failure modes
Common applications
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- rolling-contact fatigue after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- Mount the 95 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 6350 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The steeper contact angle of the large-OD 30300 family with the steeper contact angle raises axial capacity but lowers the speed ceiling against a 302/322 bearing at 95 mm bore; do not swap to the lighter family without re-checking the 1,700 r/min grease limit and the thrust load split.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 95 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- Do not confuse T (49.5 mm assembled width of cone + cup) with the cone width when drawing spacers; an abutment sized to T instead of the ring width leaves the cup unseated.
- Minimum load matters at high speed: an unloaded 30319DU at a large fraction of 1,700 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 330/355 kN ratings and 38.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30319DU (ISO 355 7GB); 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 30319DU?
30319DU is a metric 4T tapered roller bearing to ISO 355: 95 mm bore, 200 mm outside diameter and 49.5 mm assembled width T (3.74 × 7.874 × 1.949 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 330 kN, C0 355 kN, Pu 38.5 kN, grease limiting speed 1,700 r/min, oil speed 2,200 r/min, mass about 6350 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30319DU?
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 (30319DU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30319DU designation encode the 95 mm bore and what is 7GB?
last two digits 19 are the ISO bore code, ×5 = 95 mm (codes 00–03 use the 10/12/15/17 exception table). The 200 mm OD and 49.5 mm assembled T follow the ISO 355 dimension-series plan. 7GB 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 30319DU list two speeds, 1,700 and 2,200 r/min?
The lower figure, 1,700 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30319DU at 2,200 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30319DU mean?
Suffix reading on 30319DU: U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; the CA/CU/DU letter marks a contact-angle/internal-geometry variant of the same envelope — quote the exact suffix because axial/radial capacity split differs; 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.