Question: what is the difference between gray and ductile iron?
Answer: Ductile iron has a minimum tensile strength of 60,000 psi and a minimum yield strength of 40,000 psi. There are many grades of gray iron as per the ASTM A48 standard. While gray iron does not have a measurable yield strength, the range for tensile strength is 20,000 psi – 60,000 psi.