Timken478WTapered Roller Bearing Cone – 2.5591 in Bore, 1.1420 in Inner Ring Width, Straight Bore, Pressed Steel Cage, Mates With 472, 472A And 474 Cups

Product Description

What this part is: Timken 478W inch tapered roller bearing cone. Cone only. Manufacturer: Timken. Manufacturer Part Number: 478W. Cone Part Number: 478W. Base Number: 478. Series: 475. Bearing Type: Tapered Roller Bearing Cone. Number of Rows: 1. Rolling Elements: Tapered Rollers. Design Units: Inch. Bore: 2.5591 in (65.001 mm). Inner Ring Width: 1.1420 in (29.007 mm). Bore Type: Straight. Closure Type: Open. Cage Type: Pressed steel. Cage Material: Steel. Bearing Material: Case-Carburized Steel. Precision Class: Not specified. Item Weight: 8.05 lb (3.652 kg). Unit Quantity: 1 Pc. The matching single cups are the Timken 472, 472A and 474. Decoding the designation: 478 is the cone number in Timken’s 475 inch series. The W is a Timken design-variant letter on the cone, so the 478W is a distinct part from the plain 478 and carries its own published dimensions and ratings. Searchable forms of the number are 478W, 478-W, 478 W and 478. What these specs mean in practice: Dynamic Radial Load Rating C1, per row, ISO method at 1 million revolutions: 30,500 lbf (135,000 N). Dynamic Radial Load Rating C90, per row, Timken method at 90 million revolutions: 7,890 lbf (35,100 N). Dynamic Axial Rating Ca90, per row: 5,200 lbf (23,100 N). Static Radial Load Rating C0: 41,900 lbf (186,000 N). K Factor: 1.52. G1 Factor: 77.2. G2 Factor: 23. Geometry Factor Cg: 0.108. Every rating above is a single-row value for this cone. A tapered roller bearing carries combined radial and thrust load through one row of rollers running on matched cone and cup raceways, and the K factor of 1.52 is a comparatively steep raceway angle, which weights a larger share of the capacity toward thrust. C1 and C90 are two different life bases for the same bearing, so they are not interchangeable in a calculation. Maximum Temperature: 120°C. Minimum Temperature: −54°C. Harmonization Code: 8482.20.00. Mounting dimensions: Effective Center Location: −0.16 in (−4.1 mm), which places the effective centre inside the cone backface. Maximum Shaft Fillet Radius: 0.09 in (2.3 mm). Shaft Backing Shoulder Diameter, frontface (da): 2.87 in (73 mm). Shaft Backing Shoulder Diameter, backface (db): 3.03 in (77 mm). Cage Location relative to the backface (Aa): 0.04 in (1 mm). Cage Location relative to the frontface (Ab): 0.12 in (3 mm). These figures decide whether a given shaft step and fillet will clear the bearing corners and the cage. Quantity and configuration: Unit Quantity: 1 Pc. Cone only: the inner ring with its tapered roller set and pressed steel cage, as one non-separable assembly. Cone and cup mating: The matching single cups are the Timken 472, 472A and 474, giving the TS single-row assemblies 478W/472, 478W/472A and 478W/474. The cup carries no bore, no cage and no roller set: it is the outer race alone, and its raceway angle is cut to match the cone. Interchange guidance: Cross-Reference 1: SKF 478. Cross-Reference 2: NTN 4T-478. Cross-Reference 3: Bower 478. The NTN 4T prefix denotes the cone half in that maker’s scheme. The plain 478 shares the series and bore but is a separate Timken part number with its own published figures, so it is a related part rather than a direct substitute for the W variant.