Timken390-3Taper Roller Bearing Single Cone 2-1/4″ ID Class 3 Precision

Product Description

What this part is:

A Timken 390 single cone — the inner race with its tapered roller and cage assembly — from the imperial TS single-row tapered roller bearing range. Cone only. The matching cup is the Timken 394A.

Decoding the designation:

The base number 390 identifies the cone within Timken’s imperial single-cone series. The trailing -3, written on this listing also as *3, is Timken’s precision Class 3 designation, a tightened bore, runout and width tolerance grade above standard Class 4 product.

Published dimensions:

• Cone bore: 2.2500 in (57.150 mm)
• Cone width: 0.8661 in (22.00 mm)
• Assembled 390/394A: 2.2500 in bore × 4.3307 in OD × 0.8661 in width (57.150 × 110.000 × 22.00 mm)
• Mating cup 394A width: 0.7411 in (18.82 mm)
• Weight: 1.587 lb (0.72 kg)
• Material: through-hardened bearing steel

What these specs mean in practice:

A tapered roller geometry carries combined radial and axial load in one direction, with thrust capacity rising as the cup angle steepens. Class 3 precision tightens bore and raceway runout relative to standard-class product, which reduces shaft-mounted eccentricity and gives more even roller loading in gearbox and pump-shaft positions. The assembled 390/394A width of 0.8661 in equals the cone width, so the cup sits within the cone envelope in the mounted set.

Quantity and configuration:

1 Pc. Single cone, set to clearance or preload on assembly against its cup.

Interchange guidance:

390 is the base cone number; 390-3 and 390*3 are the same part written two ways. The 390A is a related size with a different bore and is a separate part number.