17-4 stainless steel 17-4 stainless steel SAE type 630 stainless steel (more commonly known as 17-4; also known as UNS 17400) is a grade of martensitic precipitation-hardened stainless steel. It contains approximately 15–17.5% (17) chromium and 3–5% (4) nickel, as well as 3–5% copper. 17-4 can be heat treated to high levels of strength and hardness, and features corrosion resistance and machinability comparable to austenitic 304 stainless. Being martensitic, 17-4 is magnetic. 17-4 is capable of being hardened up to approximately 44 Rc when heat treated to condition H900. Overaging (aging beyond the peak strength condition) improves resistance to stress corrosion cracking. Uses
The Stainless Steel Rat Hanasu - a disgraced Kekkonshiki council leader - he persuades them to reinterpret their teachings, and they embark on a more peaceful co-existence with the rest of humanity. (Incidentally "Kekkonshiki" is the romanization of the Japanese word for "Marriage Ceremony" 結婚式.) The MIT class ring, commonly referred to as "The Brass Rat", when cast in Celestrium (also known as jeweler's steel) is often referred to as "The Stainless Steel Rat" in reference to The Stainless Steel Rat series. The Chinese activist Liu Di, writing under the screen name "Stainless Steel Rat" (不锈钢老鼠), became a high-profile symbol for democracy and free