Timken385A-3Tapered Roller Bearing Cone – 2.0000 in Bore, 0.8640 in Inner Ring Width, Class 3 Precision, Pressed Steel Cage, Mates With 382A And 382 Cups

Product Description

What this part is

Timken 385A *3 inch tapered roller bearing cone. Cone only. Manufacturer: Timken. Manufacturer Part Number: 385A-3. Cone Part Number: 385A. Base Number: 385. Series: 380. Bearing Type: Tapered Roller Bearing Cone. Number of Rows: 1. Rolling Elements: Tapered Rollers. Design Units: Inch. Bore: 2.0000 in (50.8 mm). Inner Ring Width: 0.8640 in (21.946 mm). Bore Type: Straight. Closure Type: Open. Cage Type: Pressed steel. Cage Material: Steel. Bearing Material: Case-Carburized Steel. Precision Class: Class 3. Item Weight: 5.95 lb (2.699 kg). Unit Quantity: 1 Pc. The matching single cups are the Timken 382A and 382.

Decoding the designation

385 is the cone number in Timken’s 380 inch series, and the A is a Timken design-variant letter, so the 385A is a distinct part from the plain 385. The trailing 3, written -3, *3 or #3, is Precision Class 3. Class 3 holds a tighter running-accuracy tolerance than standard, which gives lower running vibration and closer shaft location. Searchable forms of the number are 385A-3, 385A *3, 385 A 3, 385A #3 and 385A.

What these specs mean in practice

Dynamic Radial Load Rating C1, per row, ISO method at 1 million revolutions: 24,200 lbf (108,000 N). Dynamic Radial Load Rating C90, per row, Timken method at 90 million revolutions: 6,280 lbf (28,000 N). Dynamic Axial Rating Ca90, per row: 3,810 lbf (16,900 N). Static Radial Load Rating C0: 24,100 lbf (107,000 N). K Factor: 1.65. G1 Factor: 42. G2 Factor: 15.7. Geometry Factor Cg: 0.0859. 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 1.65 sets the ratio of radial to thrust capacity for this geometry. C1 and C90 are two different life bases for the same bearing, so they are not interchangeable in a calculation. Harmonization Code: 8482.20.00.

Mounting dimensions

Effective Center Location: −0.12 in (−3 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): 2.36 in (60 mm). Shaft Backing Shoulder Diameter, backface (db): 2.4 in (61 mm). Cage Location relative to the backface (Aa): 0.03 in (0.8 mm). Cage Location relative to the frontface (Ab): 0.11 in (2.8 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 382A and 382, giving the TS single-row assemblies 385A/382A and 385A/382. For two-row service the matching double cups are the Timken 384ED and 384DC. A D or DC suffix on a cup marks a double cup, which carries two raceways on one outer ring and takes two cones.

Interchange guidance

A standard-tolerance 385A shares the same bore, inner ring width and raceway geometry, so it is dimensionally interchangeable, but it holds a wider running-accuracy tolerance than this Class 3 cone. The plain 385 is a separate Timken part number with its own published figures and is a related part rather than a direct substitute for the A variant.