X-type four-point contact ball bearings - KB series feature a heavy-duty four-point contact raceway design with robust cage construction and premium bearing steel, engineered to support extremely high axial loads while maintaining bidirectional load capability and excellent moment rigidity. Available in single-row and double-row configurations, with bore diameters ranging from 50mm to 600mm. These bearings deliver exceptional axial load capacity, superior shock resistance, enhanced durability under heavy loads, and long maintenance-free service life, making them ideal for large slewing rings, crane turntables, wind turbine pitch/yaw systems, stacker reclaimers, and heavy-duty material handling equipment.