Cast iron manhole covers are divided into ductile iron manhole covers and gray iron manhole covers.
Normally, the material used for gray iron manhole cover is HT200, and the material used for ductile iron manhole cover is QT500-7.
The manhole assembly produced in our Dandong Foundry is composed by ductile iron manhole cover, ductile iron manhole base, iron drum, rubber gasket and rivets.
The position of the rubber gasket on the cast iron manhole should be grinded to be flat.
The cast iron manhole cover should be tightly fitted on the base without deformation, and the manhole cover can rotate freely in the base.
Ductile Iron Manhole Cover and Base