JM738249-JM738210 bearing: complete specifications & equivalents
The JM738249-JM738210 is a ANSI ABMA 19.2 radial bearing sized 190 x 260 x 46 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 190 mm |
| Outer diameter D | 260 mm |
| Width B | 46 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 405 kN |
| Basic static load rating C0 | 720 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6840 g |
| Manufacturer designation | NTN 4T-JM738249/JM738210 |
| 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 | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 1.811 in |
| ISO bore code | 49 |
| Radial section height (D−d)/2 | 35 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) | 147 of 148 |
| Bore above smallest 4t-inch-series size | 177.3 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| JM738249 | 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 JM738249-JM738210 model number is decoded
For an inch shaft of 190 mm carrying combined radial and thrust load, NTN lists 4T-JM738249/JM738210, a single-row 4T tapered roller set of 405 kN C and 720 kN C0 inside the 260 mm OD cup. Reading the designation: 4T-JM738249/JM738210 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 JM metric-envelope family lettering ties the pair to its boundary plan. Imperial cross-check for the drawing: 190×260×46 mm converts to 7.48 × 10.236 × 1.811 in; the ABMA envelope swaps with like-numbered inch parts but the 405/720 kN ratings are NTN-specific. Cup-side note for JM738210: within the JM metric-envelope family tables the JM738249 cone is listed against several cup options, and it is the cup that fixes the 260 mm OD and the 46 mm assembled width — quote the full JM738249/JM738210 pair, never the cone alone. After bedding-in, re-check the end play of the adjusted 4T-JM738249/JM738210 pair — initial seating of the ring faces relaxes the setting slightly.
Typical equipment & failure modes
Common applications
- cement-plant mill and kiln drive trains
- large shredder and recycler main shafts
- power-plant coal-mill and fan shafts
- rolling-mill pinion stands and roll-neck auxiliaries
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
- cage fatigue when the pair runs continuously near the grease limiting speed without oil cooling
- brinell marks on cone and cup raceways from impact during handling or hammer fitting
Selection pitfalls — read before you substitute
- At 190 mm bore the 4T-JM738249/JM738210 set is adjusted with hydraulic nuts or measured shims on mill and crane positions; manual torque methods cannot control preload at the 405 kN C level.
- The J-prefixed JM738249 code belongs to a metric-envelope inch family: its 190 mm bore is a round metric figure, yet the part still follows ABMA cone/cup numbering — do not substitute an ISO 355 metric 302/322 bearing of the same bore without checking OD, T and contact angle.
- Quote the full JM738249/JM738210 pair at ordering: the JM738249 cone also ships against sibling cups, and a cup from another reference changes the 46 mm assembled width and the rating.
- Never drive the 260 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.
- Shaft and housing fillets must clear the ring chamfers of JM738249 and JM738210; use undercut shoulders so the rings seat on the face, not on a radius.
- The 405/720 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-JM738249/JM738210; 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-JM738249/JM738210?
4T-JM738249/JM738210 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 190 mm bore (7.48 in), 260 mm outside diameter and 46 mm assembled width T (10.236 × 1.811 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 405 kN, C0 720 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 6840 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-JM738249/JM738210 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the JM738249 cone or the JM738210 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 405/720 kN ratings change with the cup.
What is the difference between 4T-JM738249/JM738210 and a metric ISO 355 tapered bearing?
4T-JM738249/JM738210 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 190×260×46 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-JM738249/JM738210 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 JM738249/JM738210 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-JM738249/JM738210 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-JM738249/JM738210 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.