Elgin National Watch Company which introduced this alloy, composed of cobalt (40%), chromium (20%), iron (16%) and nickel (15%). Elgiloy offered increased resilience and strength, however, its stiffness was weak. These type of wires are still sold as alloys known as Remaloy, Forestaloy, Bioloy, Masel and Elgiloy. However, their use have decreased throughout the field of orthodontics due to the fact that no complex bends in wires are needed in today's treatment. Elgiloy is available in four levels of resilience. Blue Elgiloy (soft), Yellow Elgiloy (ductile), Green Elgiloy (semi-resilient) and Red Elgiloy (resilient). Nickel-titanium (Niti) Archwire NiTi alloy was developed in 1960 by William F. Buehler who worked at the Naval Ordnance Laboratory in Silver Springs, Maryland. The name Nitinol came from Nickel (Ni), Titanium (Ti), Naval Ordinance Laboratory (nol). The first Nickel titanium (NiTi) orthodontic alloy, introduced by Andraeson. This alloy was based on the research done by Buehler. Since their introduction, the wires made out of Niti alloys have become an important part of orthodontic treatment. The composition of the wire has 55% Nickel and 45% Titanium. The first nickel-titanium orthodontic wire alloy was marketed by the Unitek Corporation who are now known as 3M Unitek. These alloys have low stiffness, superelasticity, high springback, large elastic range and were brittle. The initial niti wires did not have shape-memory effect due to the cold-working of the wire. Thus these wires were passive and were considered as an Martensitic-Stabilized alloy. Pseudoelastic Niti archwires were commercially launched in 1986 and were known as Japanese NiTi and Chinese NiTi. Japanese Niti archwire was first produced by Furukawa Electric Co in 1978. It was first reported for usage of orthodontics by Miura et al. The Japanese alloy was marketed as Sentalloy. Heat-activated NiTi alloys became popular and commercially available in the 1990s. Chinese Niti wires were also developed in 1978 by Dr. Hua Cheng Tien at a research institute in Beijing, China. This wire was first reported in orthodontic literature by Dr. Charles Burstone. These alloys are Austentic-Active alloy and the transition from the Austenitic phase to Martensitic phase happens due to the contact of wire with a force. Copper nickel-titanium alloy In 1994 Ormco Corporation introduced this alloy. This alloy was developed with the help of Rohit Sachdeva and Suchio Miyasaki. Initially, it was available in three temperature transition forms: Superelastic (CuNiTi 27 °C), heat-activated (CuNiTi 35 °C) and (CuNiTi 40 °C).