Supply various types of manhole covers according to the customer's drawings or samples Material: Ductile iron manhole CoverFeatures:1) Moulding Process: green sand ... and engineering machinery parts, pipe fittings, valve body, fire hydrant, Manhole cover etc. We also supplygray castings as per the customer ... grade number including: QT400, QT500, QT600, QT700; HT250, HT300, TH350 Manhole Cover