Home / Standards / GB 5790-86 GB 5790-86 Hexagon flange bolts—Large series—Reduced shank—Product grade B 六角法兰面螺栓-加大系统-细杆-B级 Standard Type GB ICS N/A CCS N/A Status N/A Issue Date N/A Implementation N/A Responsible Dept N/A Drafting Unit N/A