Any wire can be bent into a sculpture, but some types of wire are preferred due to their characteristics. Aluminum wire doesn't rust in a visible way and it is easy to bend. Steel wire is easy to locate in stores but some types of steel wire will rust extensively. Copper wire is not hard to find and it oxidizes an interesting green color. Copper is difficult to bend sharply and may break. Telephone wire with colored insulation allows you to create colorful smaller sculptures. Other wires can be used as well. If you can bend and shape the wire, you can use it for sculpture.
Tools commonly used in wire sculpting include eye protection, wire cutters, pliers, hammers, anvils, vises, torches and jigs. All kinds of jigs are used to replicate shapes. A jig is a tool that you can bend the wire around to make a specific shape. Sculpting jigs are sold to help the artist make bends, corners, angles, curves and changes of direction. The most important tools are eye and hand protection from the swinging sharp edges of the wire.
Some artists approach the wire without any idea what they want to sculpt. They play with the wire until it begins to take on a form. Other artists draw out their design and execute the design in a very straightforward way. Often this will produce a sculpture that is also functional. Many intricate wire sculptures are also welded to connect wire sections together. Larger pieces may also involve different types of metal worked with wire to extend the boundaries of the wire form.
The thickness or flexibility of the wire is the most critical factor in bending the wire. If the wire is very thick or stiff, you will need to use a vise to hold the wire while you apply great force to the area you wish to bend. More flexible wire responds well to hand strength, pliers and jigs. It is a good idea to select wire based on how easily you can bend it. This reduces the amount of tools you will need to achieve the bends you want. For small works, a set of jewelry pliers will allow you to create almost any shape.