KWB 5/8" Master Link Sub Assembly - Grade 100KWB 5 8" Master Link Sub Assembly Grade 100 The KWB 5 8" Master Link Sub Assembly is designed for high capacity rigging applications where strength and safety come standard. With a working load limit of 58,700 lbs., its built to handle demanding lifts in 3 or 4 leg Grade 100 chain sling configurations. Heavy Duty Sub Assembly for Multi Leg Sling Builds Compatible with 5 8" Grade 100 chain, this assembly includes sub links designed to accept two