64450-64700-NTN bearing: complete specifications & equivalents
The 64450-64700-NTN is a ANSI ABMA 19.2 radial bearing sized 114.3 x 177.8 x 41.275 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 114.3 mm |
| Outer diameter D | 177.8 mm |
| Width B | 41.275 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 257 kN |
| Basic static load rating C0 | 375 kN |
| Limiting speed (mechanical) | 1900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3520 g |
| Manufacturer designation | NTN 4T-64450/64700 |
| 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 | 4.5 in |
|---|---|
| Outer diameter D | 7 in |
| Width B | 1.625 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 31.8 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) | 127 of 148 |
| Bore above smallest 4t-inch-series size | 101.6 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 64450-64700 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 114.3×177.8×41.275 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 64450-64700-NTN model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the order number 4T-64450/64700 denotes the pure-numeric inch family of NTN inch tapered roller bearings — cone 64450 and cup 64700 delivered as a matched, separable pair of 114.3 mm bore and 177.8 mm outside diameter. Cone and cup of 4T-64450/64700 are separately stocked parts: a worn 64700 cup can be replaced against the existing 64450 cone, provided the new cup carries the identical reference — pairing across references changes the 41.275 mm assembled width and the rating. Contact-angle geometry of the pure-numeric inch family gives 4T-64450/64700 its radial/axial load split — at 257/375 kN the static rating is about 1.46× C, typical of inch tapered sets proportioned for combined duty. Housing fitment sequence for 4T-64450/64700: press the 64700 cup square into the 177.8 mm seat first, then bring the 64450 cone (on its 114.3 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. Minimum load matters at speed: an unloaded 4T-64450/64700 run near 1,900 r/min lets the rollers skid; lightly spring-preload high-speed pair arrangements.
Typical equipment & failure modes
Common applications
- large shredder and recycler main shafts
- power-plant coal-mill and fan shafts
- rolling-mill pinion stands and roll-neck auxiliaries
- mine hoist and dragline drum shafts
Known failure patterns
- rib-face scoring when the thrust share of the combined load exceeds what the cone rib of this size carries
- 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
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- At 114.3 mm bore the 4T-64450/64700 set is adjusted with hydraulic nuts or measured shims on mill and crane positions; manual torque methods cannot control preload at the 257 kN C level.
- The pure-numeric inch family at 114.3 mm bore (177.8×41.275 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 64450/64700 reference at purchase.
- Never drive the 177.8 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 64450 and 64700; use undercut shoulders so the rings seat on the face, not on a radius.
- Fit selection follows the rotating ring: a rotating cone on a 114.3 mm shaft takes a m6/n6 seat, and a rotating cup reverses the logic — decide from the load diagram, not from habit.
- The 257/375 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-64450/64700; 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-64450/64700?
4T-64450/64700 is an inch-series single-row tapered roller bearing to the ABMA boundary plan: 114.3 mm bore (4.5 in), 177.8 mm outside diameter and 41.275 mm assembled width T (7 × 1.625 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 257 kN, C0 375 kN, grease limiting speed 1,900 r/min, oil speed 2,600 r/min, mass about 3520 g. It is an open, separable cone/cup set with a pressed-steel cage.
Are the cone and cup of 4T-64450/64700 interchangeable separately?
Yes — ABMA inch parts are individually interchangeable: the 64450 cone or the 64700 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 257/375 kN ratings change with the cup.
What is the difference between 4T-64450/64700 and a metric ISO 355 tapered bearing?
4T-64450/64700 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 114.3×177.8×41.275 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-64450/64700 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 64450/64700 references; the 4T spelling is retained among this page's search aliases.
Why does 4T-64450/64700 list two speeds, 1,900 and 2,600 r/min?
The lower figure, 1,900 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-64450/64700 at 2,600 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.