Timken99600-3Tapered Roller Bearing Single Cone — 6 in Bore, 2.5 in Width, Class 3 Precision, Case-Carburized Steel

Product Description

What this part is

A Timken 99600-3 tapered roller bearing cone: the inner ring with its ground tapered raceway, the tapered roller complement and the cage, supplied as one assembled component. Bore is 6 in (152.4 mm) and cone width is 2.5 in. Material is case-carburized bearing steel with a stamped steel cage. The 99000 block is a large-bore imperial series.

Decoding the designation

The base cone number is 99600. The trailing 3, written as 99600-3, 99600*3 or 99600#3 depending on the carton and the catalogue, is Timken’s precision Class 3 designation and not part of the base number. Class 3 tightens bore, outside diameter, width and running accuracy tolerances relative to the standard Class 2 grade in the same envelope.

What these specs mean in practice

Class 3 buys tighter geometric control, which shows up as lower radial and axial runout and a more repeatable setting when endplay is measured at assembly. On a 6 in bore that matters because the absolute error scales with size: the same angular runout produces a larger displacement at the rim than it would on a small bearing. The cost of the tighter class is a narrower fit window on the shaft journal, so journal roundness and taper have to be held correspondingly closer. Case-carburized steel gives a hard raceway over a tough core and tolerates shock loading better than a through-hardened ring.

Quantity and configuration

Cone only, comprising the inner ring, tapered rollers and cage. Sold as 1 Pc.

Fitting notes

The cone mounts as a press fit on the shaft journal, and the cup is pressed separately into the housing bore, so the two halves are installed independently and the assembly is then set to a specified endplay or preload by moving one race axially. The cone backface to-clear radius is 0.25 in and the cone frontface backing diameter is 7.05 in, which set the minimum shaft shoulder diameter and the maximum fillet radius at the shoulder. Effective centre location is -0.52 in, measured from the reference face, and is the figure used when calculating the effective load centres of a two-bearing shaft system.

Interchange guidance

A plain 99600 cone in standard Class 2 has the same size at a looser precision grade; use it only where Class 3 accuracy is not specified. Any maker’s 99600 ground to Class 3 matches this cone. Other 99000 series numbers have different bores.