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
Corrugated stainless steel tubing Corrugated stainless steel tubing Corrugated stainless steel tubing (CSST) is tubing made of stainless steel with corrugation on the inside or outside. One type is stainless steel tubing be formed with corrugated shape on outside surface. Make it higher efficiency of heat transfer, can be used to connect the form of tube soft and flexible, with good defensive displacement and vibration and noise reduction, mainly used on heat ex-changers. The other type is a type of conduit used for fuel gas distribution in buildings. It has a flexible corrugated stainless steel inner layer and an outer yellow or black plastic