Ductile iron manhole cover 1)ductile iron QT400/18,QT450/10, ... iron:HT150,HT200,HT250,D400,E600,F9 Ductile iron manhole cover 1)ductile iron QT400/18,QT450/10,QT500 ... than 200 kinds of ductile iron and grey iron manhole covers and grates 2) We also produce drain cover using ... the relevant EN124, BVQI and Australian standards 4) Form and Sizes available: square, rectangle, round, from 200mm to 1200mm 5 ...