Why is coolant not used on cast iron machining?

Coolant is often not used in cast iron machining because cast iron has Excellent thermal conductivity and tends to dissipate heat effectively on its own. Additionally, cast iron generates fine chips that can clog coolant systems, and the presence of coolant may lead to surface finish issues or corrosion. Furthermore, many machinists prefer dry machining for cast iron to achieve better tool life and surface quality.