access manhole cover 1)material:ductile iron 2)specs:QT500/7 3)ISO9001:2000 4)confirm to EN124 with different sizes 1), Round access manhole covers made by Xinxing Pipe Fittings Co., Ltdstrictly conform to standard & are free from sand hole.2), Smooth and free from sand holes, blow holes, distortion or any other defects3), Processes:a) Automatic machine linesb) Moulding boardsc) Green sand with ...