U Orthodontic Ss Wires (Round) Stainless Steel Arch Wire:    Stainless steel arch wire used through the entire treatment , but are best suited for mid-to-late stages of treatment.Orthodontic archwires may be fabricated from several alloys, most commonly stainless steel, nickel-titanium alloy (NiTi), and beta-titanium alloy (composed primarily of titanium and molybdenum).
A special alloy in the arch wire provides maximum spring while minimizing fracturing.

 They also had better formability and can be readily used to be soldered and welded for fabrication of complex orthodontic appliances. The stainless steel alloys are of "18-8" austenitic type which contain Chromium (17-25%) and Nickel (8-25%) and Carbon (1-2%). Chromium in this stainless steel alloy forms a thin oxide layer which blocks the diffusion of oxygen into the alloy and allow for the corrosion resistance of this alloy.