The Timken Company HM803110 Pinion Bearing Cup

The Timken HM803110 tapered roller bearing cup is a precision single outer-ring cup designed to work with a matching HM803145, HM803146, or HM803149 tapered roller bearing cone to carry combined radial and axial loads in heavy-duty industrial rotating equipment. Common applications include differential pinion assemblies, industrial gearboxes, conveyors, mining and aggregate equipment, agricultural machinery, and construction equipment, where reliable performance and long service life are essential under demanding operating conditions. This bearing cup is part of Timken's HM803100 series (design TS) and is constructed from high-grade bearing steel to maintain dimensional stability and fatigue resistance. Key specifications include an outside diameter of 3.5000 in (88.900 mm), an outer ring width of 0.9063 in (23.020 mm), and a maximum housing fillet radius of 0.130 in (3.30 mm); housing backing shoulder diameters Da 3.39 in (85.10 mm) and Db 2.91 in (73.91 mm). The part weighs 1.9 lb (0.8 kg) and is compatible with HM803145, HM803146, and HM803149 cones to form a complete bearing set (HM803110 with HM803145, HM803110 with HM803149). For cross-compatibility, NTN lists HM803110 as an equivalent replacement.