LL639249-LL639210 bearing: complete specifications & equivalents
The LL639249-LL639210 is a ANSI ABMA 19.2 radial bearing sized 196.85 x 241.3 x 23.812 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 196.85 mm |
| Outer diameter D | 241.3 mm |
| Width B | 23.812 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 177 kN |
| Basic static load rating C0 | 330 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2070 g |
| Manufacturer designation | NTN 4T-LL639249/LL639210 |
| 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 | 7.75 in |
|---|---|
| Outer diameter D | 9.5 in |
| Width B | 0.937 in |
| ISO bore code | 49 |
| Radial section height (D−d)/2 | 22.2 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) | 148 of 148 |
| Bore above smallest 4t-inch-series size | 184.15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| LL639249-210 | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 LL639249-LL639210 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-LL639249/LL639210 denotes the extra-light LL family of NTN inch tapered roller bearings — cone LL639249 and cup LL639210 delivered as a matched, separable pair of 196.85 mm bore and 241.3 mm outside diameter. Reading the designation: 4T-LL639249/LL639210 follows the ABMA inch convention — the number before the slash is the cone (inner ring with roller set and cage), the number after the slash is the cup (outer ring), and the extra-light LL family lettering ties the pair to its boundary plan. Selection: C 177 kN against C0 330 kN gives a C0/C ratio of 1.86 for the 196.85 mm bore; the pair is counted as one adjusted unit when checking L10 at the equivalent combined load. Cup-side note for LL639210: within the extra-light LL family tables the LL639249 cone is listed against several cup options, and it is the cup that fixes the 241.3 mm OD and the 23.812 mm assembled width — quote the full LL639249/LL639210 pair, never the cone alone. NTN grades inch 4T bearings as open bearings without integral seals; at 196.85 mm bore the application supplies sealing and the grease fill or oil feed.
Typical equipment & failure modes
Common applications
- port-crane travel and hoist gearboxes
- cement-plant mill and kiln drive trains
- large shredder and recycler main shafts
- power-plant coal-mill and fan shafts
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- flaking on one cone only when a bent shaft loads the O/X pair unevenly
- cup creep and housing fretting when the cup seat is cut too loose for the rotating load
- cage damage from a mounting blow transmitted through the roller complement
- rolling-contact fatigue spalling after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- At 196.85 mm bore the 4T-LL639249/LL639210 set is adjusted with hydraulic nuts or measured shims on mill and crane positions; manual torque methods cannot control preload at the 177 kN C level.
- The extra-light LL family at 196.85 mm bore (241.3×23.812 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full LL639249/LL639210 reference at purchase.
- Do not confuse T (23.812 mm, the assembled cone-plus-cup width) with the cone width when drawing spacers; an abutment sized to T leaves the cup unseated.
- Grease packs must leave free volume inside the 23.812 mm-wide set; over-greasing a pair churning near the oil-band speed of 1,600 r/min raises temperature and destroys the setting.
- Open 4T-LL639249/LL639210 sets have no seals: a hub or gearbox needs external sealing or the 1,200 r/min grease figure is meaningless once water reaches the cone rib.
- The 177/330 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-LL639249/LL639210; 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-LL639249/LL639210?
4T-LL639249/LL639210 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 196.85 mm bore (7.75 in), 241.3 mm outside diameter and 23.812 mm assembled width T (9.5 × 0.937 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 177 kN, C0 330 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 2070 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-LL639249/LL639210 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the LL639249 cone or the LL639210 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 177/330 kN ratings change with the cup.
What is the difference between 4T-LL639249/LL639210 and a metric ISO 355 tapered bearing?
4T-LL639249/LL639210 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 196.85×241.3×23.812 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-LL639249/LL639210 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 LL639249/LL639210 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-LL639249/LL639210 list two speeds, 1,200 and 1,600 r/min?
The lower figure, 1,200 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-LL639249/LL639210 at 1,600 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.