The square overflow cast iron manhole cover is made of "ductlie iron", a stamping process, no need to weld, and the surface is coated with asphalt paint, so that it has a good acid and alkali resistance and corrosion resistance. Overflow cast iron manhole cover is higher than the ground, convex design, large area hollow, enhance the drainage performance, but also can intercept solid matter, so that the drainage manhole cover is not blocked. Overflow cast iron manhole cover has strong stability, high strength and easy installation. And the well seat and cover integrated design, prevent theft. Our company's advantages: 1. Have their own factory, factory direct supply, no middlemen. 2. Have their own R & D team, can meet customer needs, customized according to customer needs. 3. Our company has a good after-sales service, support online technical guidance.