440C stainless steel ball has magnetism, good corrosion resistance, wear resistance and toughness. Its heat treatment process is more complex. It’s easy to crack and has high precision requirements, which is the hardest stainless steel ball in steel balls. It has the hardness of 56-58 degrees and is close to the bearing steel ball. But it has the stronger rust and corrosion performance than the bearing steel ball. The material of 440C stainless steel ball resist corrosion from water, food, alcohol, organic materials and many petroleum products. The steel ball is usually used for the industry of higher precision and anti-rust performance requirements: aviation, aerospace, bearings, motors, high-precision instruments, valves, seals refrigeration equipment, handicrafts and so on.