... for semi-trailers. 2,2'' and3.5''kingpin 3,Assembly and welding We can supply various camshafts for trucks, semi-trailers ... spare parts.3,BPW standard.4,2'' and 3.5'' kingpin5,Assembly and welding 50 and 90 kingpin 1,Huangjing Machine manufacture Co ... robot,advanced painting equipment,enable to new automatic assembly production line and automated painting line. 3,Optimized design,reasonable techniques ...