What is the type of wire formed by twisting five tempered wire over a common wire?

Coaxial Archwire Coaxial archwires are made of a central core wire of 0.006 inch diameter wire with 5 or 6 outer wires.  These wires are more flexible and were very frequently used for initial alignment of the teeth before the advent of Ni-Ti wires. Textbook of  Orthodontics Gurkeerat Singh 2nd ed pg no 335