Wire temper is a subject that I am frequently asked about. It encompasses a number of aspects including; what are the tempers of various metals ,what is it and why does it exist, and what temper wire is best for various jewelry and craft projects. This post will discuss the tempers of various metals.
Wire temper is a way to describe the stiffness and springiness of a wire and is often described in terms of harness. This chart shows the RELATIVE temper or hardness of common metals used in jewelry making. It is like the Mohs Chart used for gem and mineral hardness.
This chart shows that Fine Silver is the softest wire and Memory Wire is the hardest. It is easy to understand that Fine Silver is softer than Memory Wire, but look directly above Memory Wire and 2 down from Fine Silver and you will find Sterling Silver in BOTH places! How can that be? The hardness of Sterling Silver can be changed or tempered. This can be done by pulling the wire through dies, also called drawing down the wire, but it can also be done at home by work hardening the wire and here is an excellent video showing how you can do that. You can also soften the temper of a wire by annealing it, or heating it with a torch.
Look at the chart again and find Dead Soft Bronze and Half Hard Copper. Half Hard Copper is shown to be softer than Dead Soft Bronze because all metals have limitations as to how much softer or how much harder you can make them because of their basic chemical composition. So, this chart shows the RELATIVE Temper of the metals not their temper in absolute terms.