Technical data
Product specifications
Metric and imperial values are paired where the manufacturer provides both. Expand a section to review its parameters.
Core specifications11 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Series | 78000 | |
| Variant / construction | TDI - Tapered Double Inner | |
| Bore diameter | d | 64.987 mm |
| Outside diameter | D | 140.03 mm |
| Width | B | 66.091 mm |
| Basic dynamic load rating | C | 298 kN |
| Basic static load rating | C0 | 386 kN |
| Mass | ≈m | 4.76 kg |
| Precision class | ABMA Class 2 | |
| Sealing | Open | |
| Cage | Steel cage |
Calculation Factors6 parameters
| Parameter | Symbol | Value |
|---|---|---|
| K Factor | 0.67 | |
| Y1 Factor | 0.78 | |
| Y2 Factor | 1.16 | |
| Y0 Factor | 0.76 | |
| E Factor | 0.87 | |
| Cg Factor | 0.0884 |
Manufacturer Identity9 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Brand | Timken | |
| Material Number | 000000000100032940 | |
| World Assembly Part Number | 78255D_78551 | |
| Inner Ring Part Number | 78255D | |
| Outer Ring Part Number | 78551 | |
| Drawing Number | A-35588 | |
| Upc | 0053893402529 | |
| Official Source System | CORE BP - DS DF | |
| Official Last Run | 2026-08-23T20:02:47.157 |
Product Identity4 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Type Description | TDI - Tapered Double Inner | |
| Construction | Double Row Tapered Roller Bearing Assembly | Imperial Series | 2.5586 in Bore | 5.5130 in OD | 2.6020 in Width | Open | Cylindrical Bore | Steel Cage | Precision ABMA Class 2 | |
| Number Of Rows | 2 | |
| Tapered Bore | N |
Technical Data10 parameters
| Parameter | Symbol | Value |
|---|---|---|
| Overall Width | 0.000 mm | |
| Radial Rating | 77,200 N | |
| Axial Rating | 65,700 N | |
| Dynamic Rating C1 | 298,000 N | |
| Dynamic Rating C90 | 77,200 N | |
| Dynamic Axial Rating Ca90 | 65,700 N | |
| Dynamic Axial Rating Ca1 | 254,000 N | |
| Static Radial Rating C0 | 386,000 N | |
| Extended Dynamic Rating Ce | 0 N | |
| Static Axial Rating C0A | 487,000 N |
