Baling wire

Baling wire, otherwise known as bale wire, farm wire, or soft wire, is a type of wire used in agriculture and industry for everything from mending fences to manually binding rectangular bales of hay, straw, or cut grass. It is also used to band together corrugated cardboard, paper, textiles, aluminum and other materials that are processed in the recycling industry. 
Baling wire is commonly used in many non-agricultural applications like in the recycling industry. 
Baling wire is sometimes used in an informal, make-do manner as an easy fix. It is frequently referred to as one of the basic repair materials. Typical uses range from supporting loose mufflers to patching chain-link fences. Common phrases often include "baling wire" as an ad hoc, fix-anything material, alongside chewing gum, duct tape, and the cable tie. 
In the United States, Australia, and around the world, baling wire was used in mechanical hay balers pulled behind a tractor. The automated balers used a wire twister that first cut then twisted the ends of the wire such that the bale kept its shape after the baler had pressed the hay into a tight rectangular bale. These hay balers were in common use up until the late 1980s. When the hay was fed to livestock the wire was cut and often hung in bundles or stored in barrels or metal drums around the farm. Farmers used the soft wire for temporary repairs of almost everything you could think of on the farm, from fences, old leather horse harnesses, head stalls and bridles, to pins to keep castellated nuts in place on the tractor. Even tiny screwdrivers were made by cutting a short length of wire and looping one end for grip. The other end was then flattened and shaped to make a screwdriver for specialized tasks like replacing the tiny screws in reading glasses.
Baling wire was a commonly used product for many years before it was replaced by baling twine in the late 1970s. Small rolls of soft iron wire are readily available and used for tying rebar together and for general utility use.
Etymology.
'Baling wire' is sometimes misspelled as 'bailing wire', but 'bailing' usually refers to a leak or flood, as in bailing out a leaky rowboat with a pail, or bailing out a bank with funds to keep it afloat. 
It is also known as "haywire," from which the term "go haywire" arose, referring to crazy or mixed up from the wire's use to fix anything in an ad hoc manner.
Its closest industrial (proper name) is "Mechanic's Wire" (Soft Annealed Mechanic's Wire, 18 AWG Industrial Grade). Also sold under the name "Utility Wire".