... iron 2)ISO9001:2000 3)Japan standard ctile iron manhole cover 1)material:ductile iron 2)ISO9001:20001), ductile iron covers ... by Shunhe strictly conform to standard & are free from sand hole.2), Smooth and free from sand holes, blow holes, distortion or ... that have been properly installed and broken in normal use, free of charge after receipt of the brokencastings8), Different accessories are ...