31308‑DF.A50‑90 Tapered Roller Bearing Set 40×90×50.5mm for Rigid Shaft Support Product Overview 31308‑DF.A50‑90 is factory back‑to‑back(DF/O‑type) matched tapered roller bearing set, made up of two 31308 single tapered roller bearings. It comes with preset A50‑90 preload. This unit can support combined radial and bidirectional axial loads, delivers high rigidity for precision industrial transmission equipment. *Need a quick quote? Just send us your bearing model & quantity —