Wire is bought by grade first. 304 and 304L are the general purpose austenitic grades for forming, mesh and fasteners. 302 is the classic spring grade with slightly higher carbon and work-hardening; 316 and 316L add molybdenum for marine and chemical service; 303 contains sulphur for free machining on automatic lathes.
430 is the ferritic, magnetic, nickel-free grade for lower cost mesh and household products. 17-7 PH and 17-4 PH are precipitation hardening grades that reach very high strength after heat treatment, for springs and aerospace parts. 316LVM is vacuum melted 316L for implants and surgical devices to ASTM F138.
Duplex 2205 and super duplex 2507 give higher strength and chloride resistance for offshore fasteners and springs. Nickel alloys (625, C276, Monel) go beyond stainless for heat and acids. The choice of grade also sets the work-hardening rate, which decides how the wire behaves in drawing, springing and forming.