store 
Central Surplus Bearing Finder
A faster way to search our bearing inventory Today we’re launching the Central Surplus Bearing
Availability:
20 in stock
Timken NA78250 tapered roller bearing cone, 2.5000 in / 63.500 mm bore, 1.3085 in cone width. Cone only; the matching double cup is Timken 78549D.
List Price
$83.73
20 in stock
On the Shelf & Ready to Ship
On all orders
No Risk, No Hassle
| MFR / Brand | Timken |
|---|---|
| MPN | NA78250 |
| Model | NA 78250 |
| Bearing Type | Tapered Roller Bearing Cone |
| ID | 2.5000 in |
| Series | 78000 |
|---|---|
| Base Number | 78250 |
| Industry Terms | taper roller cone; tapered bearing inner race; TDO cone; double row taper cone; two-row taper roller inner ring; 2-1/2 bore taper cone |
| Common Misspellings | NA78250; NA7825; NA78520; NA-782-50; NA78250D; taper rolller cone; tappered bearing cone |
| Application Types | Wheel hubs; crane and hoist sheaves; mill roll necks; heavy conveyor pulleys; kiln trunnion supports |
| Bore Shaft Size | 2.5000 in / 63.500 mm (2-1/2 in) |
| Mpn Variants | NA78250; NA-78250; NA 78250; 78250; 78250-2; NA78250 TDO |
| Compatible With Replaces | Matching double cup: Timken 78549D (OD 5.5000 in). Assembly: 78250/78549D. Timken assembly numbers: 78250-90022, 78250-90023, 78250-90024, 78250-90061, 78250-90085, 78250-90095, 78250-902A2. Related cones on the same double cup: 78214, 78215C, 78255X |
| Rolling Elements | Tapered roller |
| Number Of Rows | 1 |
| Harmonization Code | 8482.20.00 |
| Cup Part Number | 78549D (double cup) |
| Part Number | NA78250 |
| Cone Part Number | 78250 |
| Cone Width | 1.3085 in (33.236 mm) |
| Cone Backface To Clear Radius | 0.09 in (2.300 mm) |
| Cone Frontface Backing Diameter | N/A |
| Cage Cone Backface Clearance | 0.24 in (6.1 mm) |
| Effective Center Location | 0.31 in (7.9 mm) |
A Timken NA78250 single-row tapered roller bearing cone: the inner ring with its tapered rollers and cage retained as one unit. Inch (imperial) series, 2.5000 in bore. Cone only. The matching double cup is the Timken 78549D, which takes two of these cones.
78250 is the cone number. The NA prefix marks a cone furnished as a component of a two-row matched assembly. 78549D is the cup number, and the D suffix on that cup identifies it as a double cup, one outer ring with two raceways. Written 78250/78549D, the pair describes a TDO assembly: Tapered Double Outer, two cone rows back to back inside a single cup.
Manufacturer: The Timken Company. Part Number: NA78250. Base Number: 78250. Cone Part Number: 78250. Cup Part Number: 78549D. Bearing Type: tapered roller bearing cone, single row, inch, TDO component. Series: 78000. Bore (d): 2.5000 in / 63.500 mm. Cone Width (B): 1.3085 in / 33.236 mm. Raceways On This Ring: 1. Rolling Elements: tapered rollers. Cage Type: stamped one-piece roller cage. Cage Material: stamped steel. Bearing Material: case-carburized alloy steel. Closure Type: open. Mounting Arrangement: TDO, Tapered Double Outer, two cone rows back to back in one double cup. Cone Backface To Clear Radius (R): 0.09 in / 2.300 mm. Cone Backface Backing Diameter (db): 3.35 in / 85 mm. Cage-Cone Backface Clearance (Aa): 0.24 in / 6.1 mm. Design Units: inch (imperial). Harmonization Code: 8482.20.00. Country of Origin: United States.
Timken publishes the following for the complete two-row 78250/78549D assembly. Cup Outside Diameter (D): 5.5000 in / 139.700 mm. Double Cup Width (C): 2.0395 in / 51.803 mm. Bearing Width Across Cones (T): 3.0625 in / 77.788 mm. Cup Backface To Clear Radius (r): 0.06 in / 1.5 mm. Cup Frontface Backing Diameter (Da): 5.19 in / 131.83 mm. Effective Center Location (a): 0.31 in / 7.9 mm. Dynamic Radial Rating, one row, 90M revs (C90): 11,800 lbf / 52,600 N. Dynamic Radial Rating, two row, 1M revs (C1): 79,300 lbf / 353,000 N. Dynamic Radial Rating, two row, 90M revs (C90(2)): 20,600 lbf / 91,500 N. Dynamic Thrust Rating, 90M revs (Ca90): 17,500 lbf / 77,900 N. K Factor: 0.67. e Factor: 0.87. Y1: 0.78. Y2: 1.16. Geometry Factor (Cg): 0.0884. Related Timken assembly numbers: 78250-90022, 78250-90023, 78250-90024, 78250-90061, 78250-90085, 78250-90095, 78250-902A2.
Two cone rows seated back to back in one double cup carry thrust in both directions and give a wide effective bearing spread, which resists overturning moment from a short shaft section. That spread is why the arrangement appears in wheel hubs, crane sheaves and roll necks. TDO bearings run in fixed positions or float in the housing bore. As a single cone, this part is one of the two inner rings in that assembly.
Unit Quantity: 1 Pc. One cone assembly: inner ring, rollers and cage. The 78549D double cup and any spacer are separate part numbers, and a complete TDO uses two cones.
78250 is the industry cone number and carries unchanged across the inch tapered interchange. Cones 78214, 78215C and 78255X also run against the 78549D double cup, each at a different bore. The Timken 78250 carries the same raceway geometry as this NA78250.
Rockwell’s own product page for the Kinetix 6000 is down
A faster way to search our bearing inventory Today we’re launching the Central Surplus Bearing
When an HMI panel goes dark or a PLC module stops communicating, the machine it
If you have ever watched a machine glide smoothly back and forth, tracing a perfect
Our team can locate, cross-reference, and source all parts.
Our team can locate, cross-reference, and source all parts.
Sort
Brand
Price
MPN
Categories
