50 Inch Four-Point Contact 1260x1540x110 mm Ball Slewing Ring Bearing with No Gear50 Inch Four Point Contact 1260x1540x110 mm Ball Slewing Ring Bearing with No Gear Four Point Contact Ball Slewing Bearing with no Gear A slewing bearing ring is a rotational rolling element bearing that typically supports a heavy but slow turning or slow oscillating load, often a horizontal platform such as a conventional crane, or the wind facing platform of a horizontal axis windmill. (To 'slew' means to turn without change of place.) Item Outside