Timken29681-3Tapered Roller Bearing Cone 2.781 in Bore Inch Series Class 3 Precision Cone Only

Product Description

What this part is

A tapered roller bearing cone in the Timken inch series: the inner ring, complete with its roller set and cage. Bore 2.781 in (70.638 mm).

Decoding the designation

29681 — the cone number in the 29600 inch series family.
-3, also written *3 or #3 — Timken precision Class 3, a tighter tolerance grade than standard.

Quantity and configuration

1 Pc. Cone only. The matching cup is the Timken 29620.

What these specs mean in practice

A tapered roller bearing splits into two separable halves: the cone carries the inner raceway, the rollers and the cage, and the cup is the outer race. The raceway angle and roller path are matched between the two halves of a published pairing. Class 3 tightens the bore and raceway running tolerances relative to a standard cone, which reduces runout in the assembled bearing and makes endplay settings repeatable from one unit to the next. Tapered geometry carries heavy radial load together with thrust in one direction, so these bearings normally run in opposing pairs, with the setting between them establishing endplay or preload.

Fitting notes

The cone is an interference fit on the shaft and is driven square against its shoulder before the setting is taken. Endplay is adjusted after both halves of both bearings are seated.

Interchange guidance

This is the cone half of the Timken 29681/29620 pairing. The 29680 and 29685 cones share the same 29620 cup but differ in width, and a standard-precision 29681 without the Class 3 suffix is the same envelope at a looser tolerance grade — all related sizes rather than interchanges.