TQO (Straight Bore Four-Row Assembly) TQO bearings are directly mounted and comprised of two double inner races, two single and one double outer race, with an inner race spacer and two outer race spacers. Slots in the inner race spacer permit lubricant to flow from the bearing chamber to the roll neck. The inner race spacers are hardened to minimize face wear.Four-row cylindrical roller bearings are used almost exclusively for the roll necks of rolling mill stands, calenders and roller presses. 

In four-row cylindrical roller bearings, the rollers are guided between integral or non-integral flanges on the outer ring. The inner ring is without flanges; axial displacement of the shaft with respect to the housing can therefore be accommodated by the bearing within certain limits.