This hub is the rotating interface between the front drive shaft and the roller assembly inside the baler. It supports the roller journal and transmits torque from the driveline into the baler’s pickup or feeding mechanism. A worn hub causes radial play that misaligns the roller, leading to uneven belt tension and premature bearing failure. The manufacturer machines the bore and flange face to the same tolerances as the original assembly, so the roller shaft seats squarely without shimming. On reinstall, clean the mating surfaces and torque the retaining fasteners to the specification for the host machine.