TimkenTapered Roller Bearing Cone, Class 3 Precision – 5.0625 in Bore, 1.2500 in Width, Series 48500, Matching Cup 48750

Product Description

What this part is

Timken 48506-3 is an inch-series tapered roller bearing cone — the inner ring with its tapered roller and cage assembly. Series: 48500. Bore: 5.0625 in (128.588 mm). Inner ring width (B): 1.2500 in (31.750 mm). Bore form: straight. Cone only. The matching cup is the Timken 48750.

Decoding the designation

Precision Class: Class 3, marked on the carton as 48506 *3 and 48506 #3. Class 3 holds tighter bore, width and running-accuracy tolerances than standard, which lowers runout and vibration in service and locates the shaft more closely. Base number: 48506. Series: 48500.

What these specs mean in practice

Ratings below are per row, for the 48506 cone running against its matching cup. Dynamic radial load rating C1, at 1 million revolutions: 39,800 lbf (177,000 N). Dynamic radial load rating C90, at 90 million revolutions: 10,300 lbf (45,900 N). Dynamic axial rating Ca90: 11,500 lbf (51,300 N). Static radial load rating C0: 67,400 lbf (300,000 N). K factor: 0.89. A K factor of 0.89 comes from a steep raceway angle, which biases the bearing toward thrust capacity: Ca90 here is higher than C90, so the row carries more thrust than radial load at the 90-million-revolution life.

Quantity and configuration

One piece: one 48506 cone, comprising the inner ring, the tapered rollers and the cage. Single row. Rolling elements: tapered rollers. Cage: stamped steel. Bearing material: case-carburized steel. Open, unsealed. Effective centre location: 0.65 in (16.5 mm) outside the cone backface.

Mounting dimensions

Shaft backing shoulder diameter, frontface (da): 5.47 in (139 mm). Shaft backing shoulder diameter, backface (db): 5.71 in (145 mm). Maximum shaft fillet radius: 0.14 in (3.600 mm). Cage location relative to backface (Aa): 0.16 in (4.1 mm). Cage location relative to frontface (Ab): 0.06 in (1.5 mm). Weight: 7.00 lb (3.2 kg).

Fitting notes

Cones of this type mount in opposing pairs on a shaft, and the bearing is set by axial adjustment or shim against the opposing row. Geometry factor Cg: 0.178, used in the lubrication life adjustment factor a3l. Lubrication: oil or grease. Cone and cup raceway angles are matched to each other, so the 48750 is the cup that produces the published ratings.

Interchange guidance

Searchable forms of the designation: 48506-3, 48506 *3, 48506 #3, 48506-3 cone, 48506. Class 3 precision is written -3, *3 and #3 interchangeably. A plain 48506 with no suffix carries standard tolerance rather than Class 3.