Timken5757TTapered Roller Bearing Cone, Tapered Bore 3.170 in Large End x 3.017 in Small End

Product Description

What this part is

A Timken 5757T tapered roller bearing cone — the inner ring complete with its tapered rollers and cage — built with a tapered bore rather than a straight one. The bore measures 3.170 in at the large end and 3.017 in at the small end.

Quantity and configuration

1 Pc. Cone only.

Decoding the designation

5757 is the cone number, which fixes the bore, the cone width and the raceway angle together. The T suffix marks the tapered-bore version of the cone, which is why the listing carries two bore readings rather than one.

What a tapered bore buys

A tapered bore seats on a matching tapered shaft journal, and the interference fit is set by how far the cone is driven up the taper rather than by a fixed diametral tolerance. That gives an adjustable fit: the same cone can be set to a chosen ring expansion, and it can be removed and refitted without the pressing damage a heavy straight interference fit tends to cause. It is the arrangement used on rolling mill roll necks and other heavy journals that are reground over their life, since a reground journal is accommodated by driving the cone slightly further on.

What these specs mean in practice

The cone assembly is a unit in service: inner ring, rollers and cage are not separable, and the rollers are matched to that ring. The raceway angle built into the number divides the load between radial and axial, so the cone runs correctly only against a cup ground to the same angle.

Fitting notes

A tapered-bore cone is drawn up its journal to a measured position, with the fit checked by ring expansion or by axial drive-up distance rather than by feel. Force is taken on the inner ring back face only, never through the rollers or the cage. Bearing setting follows once both races are seated.

Interchange guidance

A straight-bore 5757 is a different part: the bore geometry, the mounting method and the shaft it fits all change, so it is not a substitution for the T version. Interchange requires a cone marked 5757T with the same tapered bore, and it has to run against the cup ground to the matching raceway angle.