How to pick the hardness of your desired wire
Hardness is the measurement of the malleability or temper of a substance. When purchasing raw materials for wire-work, you will find that wire comes in several different levels of hardness, only a few of which are commonly used by jewelers. The most typical jewelry wire can be categorized into three groups: Hard, half-hard, or dead soft.
Gauge/Thickness:
Keep in mind that the gauge (thickness) of the wire will also have an effect on its hardness. For example, a piece of 12 gauge wire is relatively thick, and even at dead soft hardness will not bend as easily as 18 gauge wire of the same hardness. Large wire is not recommended for the beginner.