Cutting through cast iron with a circular saw is not recommended. Cast iron is a very hard and brittle material that can pose challenges when it comes to cutting. While a circular saw is a powerful tool, it is generally not suitable for cutting through cast iron.
Cast iron is commonly cut using specialized tools such as an angle grinder with a cutting wheel specifically designed for metal or a reciprocating saw with a metal-cutting blade. These tools are better equipped to handle the hardness and density of cast iron.
If you need to cut cast iron, it's advisable to use the appropriate tools and take proper safety precautions. It's also recommended to wear protective gear such as safety goggles, gloves, and a face mask to prevent injury and minimize exposure to dust or debris.