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
Braided stainless steel brake lines additional rubber outer sheath, braided stainless steel hoses typically consist of a Teflon® or generic PTFE (polytetrafluoroethylene) inner hose wrapped in a braid consisting of stainless steel wire. The stainless wire braid more effectively resists expansion due to pressure inside the hose core. This improves brake system effectiveness by more directly transferring operator input (hydraulic pressure) to brake friction surfaces. While available without a coating, the stainless braid is typically coated or covered with a clear or colored material such as PVC (polyvinyl chloride) to protect the wire and inner hose from the elements and chemicals, to protect the vehicle