TimkenClass 00 Precision Tapered Roller Bearing Cone Only, 2.0000 in Bore x 0.7190 in Inner Ring Width, Inch Series – Mating Cup Not Included

Product Description

What this part is

This is the cone half of a single-row tapered roller bearing — the inner ring with its ground tapered raceway, the tapered rollers, and the cage that holds them, supplied as one non-separable assembly. It is the Timken 18200 cone, 2.0000 in (50.8 mm) bore by 0.7190 in (18.263 mm) inner ring width, in Class 00 precision. The cone is the half that presses onto the shaft.

What is and is not included

This listing is the cone only. No cup is included. A tapered roller bearing is two separately numbered halves: the cup (outer ring) presses into the housing, the cone (inner ring plus rollers plus cage) presses onto the shaft. Cups and cones are supplied apart as standard practice because they mount in different members and wear at different rates.

Mating cup references

The 18200 cone runs against cups in Timken’s 18300 series. Timken’s catalogue entry for the 18200 lists 18335E and 18335X among its related cups, with further options in the series. The widely quoted complete assembly for this cone is 18200 / 18337. More than one cup reference is valid for this cone.

Class 00 precision

The “#00” / “*00” marking carried on this cone is a Timken precision class designation, not a variant part number. Timken’s inch tapered roller classes run from standard through Class 3 to Class 0 and Class 00, with each step tightening the tolerances. Class 00 is tighter than Class 3 and is the top of the commercially available inch precision ladder.

Class 00 tightens control on the bore and on the raceway geometry, and tightens running accuracy, giving less radial and axial runout as the bearing turns. That applies where the bearing sets the position of a component rather than merely supporting it: machine-tool spindles, precision gearboxes and index heads, grinding and boring positions, measuring and test equipment. In those positions bearing runout transfers straight into the workpiece or the gear mesh.

A Class 00 cone costs materially more than a standard-class 18200 because it takes extra grinding and gauging to produce.

Published ratings and mounting data

Load ratings below are Timken’s published figures for the 18200 cone reference. They describe the complete single-row assembly, cone plus its mating cup, rather than the cone in isolation. Bore, inner ring width, weight and shaft abutment figures are cone-specific.

Cone bore (d): 2.0000 in / 50.8 mm. Inner ring width (B): 0.7190 in / 18.263 mm. Precision class: Class 00. Dynamic radial load rating C1 (1 million revolutions, ISO method): 13,700 lbf / 61,100 N. Dynamic radial load rating C90 (90 million revolutions, Timken method): 3,560 lbf / 15,800 N. Dynamic axial rating Ca90: 3,470 lbf / 15,400 N. Static radial load rating C0: 14,400 lbf / 63,900 N. K factor: 1.03. Effective centre location (a): 0.08 in / 2 mm. Maximum shaft fillet radius cleared: 0.06 in / 1.5 mm. Shaft backing shoulder diameter, frontface (da): 2.2 in / 56 mm. Shaft backing shoulder diameter, backface (db): 2.32 in / 59 mm. Cage location relative to backface (Aa): 0.07 in / 1.8 mm. Cage location relative to frontface (Ab): 0.09 in / 2.3 mm. G1 factor: 26.1. G2 factor: 20.3. Geometry factor Cg: 0.0852. Cone weight: 2.8 lb / 1.3 kg.

What these specs mean in practice

The K factor of 1.03 is low for a tapered roller bearing. K is the ratio of radial to thrust capability, set by the cup angle: a lower K means a steeper angle and more thrust capability for a given radial load. At 1.03 this bearing is close to balanced, with a published Ca90 of 3,470 lbf against a C90 of 3,560 lbf. That is a steep-angle bearing for positions where axial load is a serious part of the duty, such as a machine-tool spindle or a bevel or helical gearbox shaft.

C1 and C90 are the same bearing described at two different life bases: C1 of 13,700 lbf at one million revolutions on the ISO method, C90 of 3,560 lbf at ninety million revolutions on Timken’s method.

Quantity and configuration

Priced and sold per single cone. Single-row tapered roller bearings normally work in opposed pairs, because one row resists thrust in one direction only, so a typical shaft takes two cones and two cups.

Mounting data

The cone is an interference fit on the shaft. Maximum shaft fillet radius cleared: 0.06 in / 1.5 mm. Shaft backing shoulder diameter, frontface (da): 2.2 in / 56 mm. Shaft backing shoulder diameter, backface (db): 2.32 in / 59 mm.

A tapered roller bearing has no built-in internal clearance. Operating clearance or preload is created at assembly by how far the cone is drawn up against the cup, and that setting is the largest single determinant of both bearing life and spindle accuracy.

Interchange guidance

18200 is an industry-standard inch cone designation rather than a Timken-proprietary code, and cones to this number are produced by several manufacturers, so a same-number cone from another maker is dimensionally interchangeable in the standard class. The precision class does not interchange: a standard-class 18200 fits the same envelope without delivering Class 00 running accuracy.

Searchable forms: 18200, 18200-00, 18200 #00, 18200 *00, 18-200, 18 200, K-18200, and the unsuffixed standard-class 18200. Cups and assemblies: 18337, 18335E, 18335X, 18200/18337, 18200-18337, 18200/18335E.