Cast iron manhole covers are divided into ductile iron manhole covers and gray iron manhole covers, generally speaking, the same weight of ductile iron manhole covers than gray iron manhole cover pressure resistance. The material used for gray iron manhole cover is generally HT200, and the material used for ductile ink manhole cover is generally QT500-7.

The characteristics of spheroidal ink manhole cover:

Good toughness. The impact value is similar to that of medium carbon steel and more than 10 times that of gray iron.

Strong corrosion resistance. Water spray corrosion test, 90 days of corrosion is only 1/40 steel pipe, is 1/10 gray iron pipe. The service life is 2 times that of gray iron pipe and 5 times that of ordinary steel pipe.

Good plasticity. Elongation ≥7%, similar to high carbon steel material, while gray iron material elongation is zero.

High strength. Tensile strength ob ≥420MPa, yield strength os ≥300MPa, and low carbon steel is the same, is three times of gray iron material.

Application: municipal road, highway, communication, power, tap water, community, school and other parks.