L630349-L630310 bearing: complete specifications & equivalents
The L630349-L630310 is a ANSI ABMA 19.2 radial bearing sized 152.4 x 192.088 x 25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 152.4 mm |
| Outer diameter D | 192.088 mm |
| Width B | 25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 144 kN |
| Basic static load rating C0 | 261 kN |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1570 g |
| Manufacturer designation | NTN 4T-L630349/L630310 |
| 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-inch-series range
| Bore d | 6 in |
|---|---|
| Outer diameter D | 7.563 in |
| Width B | 0.984 in |
| ISO bore code | 49 |
| Radial section height (D−d)/2 | 19.8 mm |
| Smallest bore in 4t-inch-series | 12.7 mm |
| Largest outer diameter in 4t-inch-series | 260 mm |
| Width range across 4t-inch-series | 10.998–77.788 mm |
| Bore position in 4t-inch-series (smallest first) | 141 of 148 |
| Bore above smallest 4t-inch-series size | 139.70000000000002 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| L630349 | 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 L630349-L630310 model number is decoded
4T-L630349/L630310 is the NTN 4T catalogue entry for a 152.4×192.088×25 mm inch tapered roller bearing — an ABMA-dimensioned cone/cup set, not an ISO 355 metric bearing, even though the table quotes metric equivalents. Unlike ISO 355 metric numbers, this ABMA code does not encode the bore arithmetically: L630349 identifies the cone of 152.4 mm (6 in) bore by catalogue lookup, and L630310 fixes the 192.088 mm OD. Imperial cross-check for the drawing: 152.4×192.088×25 mm converts to 6 × 7.563 × 0.984 in; the ABMA envelope swaps with like-numbered inch parts but the 144/261 kN ratings are NTN-specific. Cup-side note for L630310: within the light L family tables the L630349 cone is listed against several cup options, and it is the cup that fixes the 192.088 mm OD and the 25 mm assembled width — quote the full L630349/L630310 pair, never the cone alone. The rollers run with their large ends against the cone's guide rib; lubricant must reach that rib face of 4T-L630349/L630310, not only the raceway, or the pair smears on the first overloaded start.
Typical equipment & failure modes
Common applications
- heavy press and forging-machine drive shafts
- port-crane travel and hoist gearboxes
- cement-plant mill and kiln drive trains
- large shredder and recycler main shafts
Known failure patterns
- cone-rib and roller large-end smearing when the adjusted pair runs with preload but starved lubricant film
- false brinelling on a stationary pair exposed to vibration during transport or standby
- preload loss and noise after one bearing of the adjusted pair is replaced without resetting end play
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- At 152.4 mm bore the 4T-L630349/L630310 set is adjusted with hydraulic nuts or measured shims on mill and crane positions; manual torque methods cannot control preload at the 144 kN C level.
- The light L family at 152.4 mm bore (192.088×25 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full L630349/L630310 reference at purchase.
- Never drive the 192.088 mm cup home through the rollers: fitting force goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Grease packs must leave free volume inside the 25 mm-wide set; over-greasing a pair churning near the oil-band speed of 2,100 r/min raises temperature and destroys the setting.
- Grease packs must leave free volume inside the 25 mm-wide set; over-greasing a pair churning near the oil-band speed of 2,100 r/min raises temperature and destroys the setting.
- The 144/261 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-L630349/L630310; internal geometry legitimately differs between inch-series makers, so re-verify ratings, adjustment and the exact cone/cup references before substituting another brand on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 4T-L630349/L630310?
4T-L630349/L630310 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 152.4 mm bore (6 in), 192.088 mm outside diameter and 25 mm assembled width T (7.563 × 0.984 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 144 kN, C0 261 kN, grease limiting speed 1,600 r/min, oil speed 2,100 r/min, mass about 1570 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-L630349/L630310 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the L630349 cone or the L630310 cup can be replaced by an identical reference from NTN or another ABMA-dimensioned maker. Pairing the cone with a different cup reference is a different catalogue row: OD, assembled T and the 144/261 kN ratings change with the cup.
What is the difference between 4T-L630349/L630310 and a metric ISO 355 tapered bearing?
4T-L630349/L630310 follows the ABMA inch boundary plan with cone/cup references; ISO 355 bearings use metric dimension-series numbers (302, 322, …). Even where a metric size looks close to 152.4×192.088×25 mm, the envelopes and contact angles differ — the two systems are not drop-in interchangeable; check every boundary value before substituting.
What does the 4T prefix on 4T-L630349/L630310 mean?
4T is NTN's tapered roller bearing quality mark, stamped on cone and cup in the factory. It identifies NTN's 4T programme and is not a dimension or variant code, so interchange lists quote the bare L630349/L630310 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-L630349/L630310 list two speeds, 1,600 and 2,100 r/min?
The lower figure, 1,600 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 4T-L630349/L630310 at 2,100 r/min because oil removes rib-contact heat better. Real limits still depend on pair adjustment, oil flow and cooling.
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.