850*850 MM MANHOLE COVER WITH FRAME

Ductile Iron Manhole Cover features:

1. High strength:The tensile strength of ductile iron is more than 420Mpa and the yield strength is more than 300MPa, three times more than gray iron.

2. Good toughness: impact value is similar to carbon steel and 10 times than grey iron.

3. Good plasticity. Elongation of ductile is more than 7% which is similar with high-carbon steel, gray iron material and extend rate is zero.

4. Anti-corrosion resistance: The corrosion was only 0.25 times of pipes during ninety days spray corrosion test and 0.1 times of gray iron pipes. The life is 2 times longer than gray iron pipes and 5 times longer than ordinary steel pipe. 

5. Applied In most municipal applications: water, salt water, steam, the corrosion resistance and oxidation resistance of cast iron are more than steel. Because of the spherical graphite cast iron microstructure, ductile iron does better than steel in reduced vibration capacity.