TimkenTapered Roller Bearing Cone 2-7/8 in Bore, Class 3 Precision, Single Row

Product Description

What this part is

A Timken 42683-3 tapered roller bearing cone: the inner ring complete with its roller set and cage, with a 2-7/8 in bore. Cone only. A cone runs against a matching cup, which is a separate part number.

Decoding the designation

The 42683 base number places the cone in Timken’s inch tapered roller programme. The trailing *3, also written -3 or #3, is Timken precision Class 3: a tighter bore and running accuracy grade than standard tolerance.

What these specs mean in practice

The roller taper is what lets one row carry radial and axial load together, with the thrust reaction rising as the taper angle steepens. Class 3 controls bore tolerance and raceway runout, so the bearing can locate a shaft rather than only carry it, and the tighter bore changes the journal diameter the cone is fitted to.

Quantity and configuration

One cone, single row.

Fitting notes

The cone is an interference fit on the shaft and is pressed on the inner ring face only, never through the rollers. Running clearance or preload is set against the mating cup on assembly, measured at the shaft.

Interchange guidance

A 42683 cone at standard tolerance rather than Class 3 is a related size, since the precision grade is the substance of this part number. Cone and cup raceway angles are matched between the two halves of a given Timken pairing.