T7FC055 bearing: complete specifications & equivalents
The T7FC055 is a ISO 355 radial bearing sized 55 x 115 x 34 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 55 mm |
| Outer diameter D | 115 mm |
| Width B | 34 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 137 kN |
| Basic static load rating C0 | 156 kN |
| Limiting speed (mechanical) | 3300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1570 g |
| Manufacturer designation | NTN T7FC055 |
| 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 & T7FC-series range
| Bore d | 2.165 in |
|---|---|
| Outer diameter D | 4.528 in |
| Width B | 1.339 in |
| ISO bore code | 55 |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in T7FC-series | 45 mm |
| Largest outer diameter in T7FC-series | 160 mm |
| Width range across T7FC-series | 29–45 mm |
| Bore position in T7FC-series (smallest first) | 3 of 6 |
| Bore above smallest T7FC-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| T7FC055 | 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 T7FC055 model number is decoded
The NTN 2203E table prints T7FC055 in the large-size ISO 355 tapered-roller family: 55 mm bore, 115 mm cup OD, 34 mm T, with a grease limiting speed of 3,300 r/min and an oil-lubricated ceiling of 4,400 r/min. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders T7FC055 by the metric ISO 355 number (ISO series abbreviation 7FC): 55 mm bore, 115 mm OD. At 137 kN C the bearing offers about 2.5 kN of dynamic capacity per millimetre of the 55 mm bore — compare any substitution on this ratio and the 34 mm assembled T, not on bore alone. Imperial cross-check for the drawing: 55×115×34 mm is 2.165 × 4.528 × 1.339 in; ISO 355 makes the envelope interchangeable but C/C0, 137/156 kN, is NTN-specific. Open 4T bearings need application seals; without them the grease at the cone rib of T7FC055 washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
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
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 55 mm bore class are commonly adjusted in pairs; verify end play against the axle drawing and re-torque after bedding-in rather than trusting the initial preload on T7FC055.
- The large-size ISO 355 tapered-roller family at 55 mm bore (115×34 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,400 r/min oil ceiling.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 55 mm shoulder geometry, because retrofitting flips the cups.
- Do not confuse T (34 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.
- Open T7FC055 units have no seals: a wheel-hub or gearbox application needs external sealing or the 3,300 r/min grease figure is meaningless once water reaches the cone rib.
- The 137/156 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for T7FC055 (ISO 355 7FC); 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 T7FC055?
T7FC055 is a metric 4T tapered roller bearing to ISO 355: 55 mm bore, 115 mm outside diameter and 34 mm assembled width T (2.165 × 4.528 × 1.339 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 137 kN, C0 156 kN (2203E prints no Pu for this size), grease limiting speed 3,300 r/min, oil speed 4,400 r/min, mass about 1570 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on T7FC055?
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 (T7FC055); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the T7FC055 designation encode the 55 mm bore and what is 7FC?
trailing dimension block 055 prints the 55 mm bore directly for this large-size T-code. The 115 mm OD and 34 mm assembled T follow the ISO 355 dimension-series plan. 7FC 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 T7FC055 list two speeds, 3,300 and 4,400 r/min?
The lower figure, 3,300 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates T7FC055 at 4,400 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on T7FC055 mean?
The T2/T4/T7-style code is NTN's large-size tapered roller designation within ISO 355; it identifies the dimension series and 55 mm bore directly, and remains an open 4T execution ordered under its own code.
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.