31 Inch Four-Point Contact 778x1022x100 mm Ball Slewing Ring Bearing with No Gear31 Inch Four Point Contact 778x1022x100 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