Gray cast iron is characterized by high compressive strength and relatively low tensile strength. This disparity stems primarily from its internal flake graphite structure, which tends to cause stress concentrations under tension; consequently, while its overall toughness is inferior to that of steel, it performs reliably under compressive loads.
Gray cast iron offers excellent vibration-damping properties and thermal conductivity. The flake graphite absorbs vibrational energy, making the material ideal for applications requiring vibration reduction, such as machine tool bases and equipment housings. Its good thermal conductivity also makes it suitable for components requiring heat dissipation-such as engine blocks-as it facilitates uniform temperature distribution.
Gray cast iron exhibits excellent machinability; chips break easily, and tool wear is minimal during processing, making it highly suitable for mass-production machining. This offers significant economic advantages in the machinery manufacturing industry, leading to its widespread use even in components requiring high machining precision.
Gray cast iron also demonstrates outstanding wear resistance and dimensional stability, performing particularly well in sliding friction applications with adequate lubrication. However, it has relatively poor impact resistance and is prone to cracking under impact loads or at points of stress concentration; therefore, designs and operational practices generally aim to avoid conditions involving severe impact.