Timken581-3/572B-3Tapered Roller Bearing Set, TSF Flanged Cup, Class 3 Precision – 3.1875 in Bore, 5.5115 in OD, 1.4375 in Width, Series 575

Product Description

What this part is

Timken 581-3/572B-3 is an inch-series tapered roller bearing assembly in the TSF configuration — Tapered Single with Flange. Series: 575. Bore: 3.1875 in (80.963 mm). Outside diameter: 5.5115 in (139.992 mm). Assembly width (T): 1.4375 in (36.513 mm). Inner ring width (B): 1.4212 in (36.098 mm). Outer ring width (C): 1.125 in (28.575 mm).

Decoding the designation

Cone part number: 581. Cup part number: 572-B. Precision Class: Class 3, marked on both halves as 581 *3 and 572B *3. Class 3 holds tighter bore, outside diameter and width tolerances and tighter running accuracy than standard, which lowers runout and vibration in service and locates the shaft more closely. The B on the cup designates the flanged cup. Outer ring flange O.D.: 5.6700 in. Outer ring flange width: 0.1875 in.

What these specs mean in practice

Dynamic radial load rating C1, at 1 million revolutions: 46,500 lbf (207,000 N). Dynamic radial load rating C90, at 90 million revolutions: 12,100 lbf (53,600 N). Dynamic axial rating Ca90: 8,330 lbf (37,100 N). Static radial load rating C0: 65,400 lbf (291,000 N). K factor: 1.45. e factor: 0.40. Y factor: 1.49. The K factor of 1.45 fixes the ratio of radial to thrust capacity set by the raceway angle, and the e and Y factors convert combined radial and thrust loading into the equivalent radial load used for life calculation. A flanged cup locates axially against the face of a through-bored housing and aligns the seal bore, so the housing needs no machined backing shoulder.

Quantity and configuration

One assembly, two pieces: one 581 cone carrying the rollers and cage, and one 572-B flanged cup. Single row. Rolling elements: tapered rollers. Cage: stamped steel. Bearing material: case-carburized steel. Open, unsealed. Effective centre location: –0.21 in (–5.3 mm), inside the cone backface.

Mounting dimensions

Shaft backing shoulder diameter, frontface (da): 3.54 in (90 mm). Shaft backing shoulder diameter, backface (db): 3.78 in (96 mm). Housing backing shoulder diameter, frontface (Da): 5.25 in (133.35 mm). Housing backing shoulder diameter, backface (Db): 4.92 in (124.97 mm). Maximum shaft fillet radius: 0.14 in (3.600 mm). Maximum housing fillet radius: 0.130 in (3.30 mm). Weight: 4.8 lb (2.2 kg).

Fitting notes

Cone and cup mount as a pair, normally in opposing pairs on a shaft. Bearing setting is made by axial adjustment against the opposing row or by shim, and the K factor governs the induced thrust reaction. G1 factor: 125.7. G2 factor: 32. Geometry factor Cg: 0.13, used in the lubrication life adjustment factor a3l. Lubrication: oil or grease.

Interchange guidance

Searchable forms of the designation: 581-3/572B-3, 581 *3 / 572B *3, 581#3/572B#3, 581/572B, 581 572 B, 572-B, 572B, 581. Class 3 precision is also written *3 and #3. The unflanged cup that runs on the same 581 cone is the 572, a related size with no locating flange, a 5.5115 in plain outside diameter and a different housing fit. A plain 581/572 set carries standard tolerance rather than Class 3.