Whether you are starting on a career as a blacksmith or simply repairing a car or building, it can be helpful to know the dynamics of bending metal. If you keep in mind a few basic principles, you can learn the best way to bend metal.
Bending Metal With Heat
Metal's crystalline structure makes it more malleable when heated. It can easily be bent when it's very hot. Sources you can use to heat metal include: propane or oxygen-acetylene torches, a forge and a hot fire. Some heat sources, however, may be too hot for a particular metal. For steel or aluminum, heat the metal until it is red hot. For most other metals, it usually is not necessary to use heat, but if you have to, heat them slightly and avoid heating metals, such as brass or copper, which melt very easily. Once, the metal is heated, use a hammer or tongs to beat a bend into the metal. This can be done with shear strength or with a mechanical aid, such as a press. When bending a hot metal, apply pressure to as small an area as possible to minimize strain on the metal. If you use a hammer, try to bend the metal around a template; hot metal is very easy to over-bend. Once the metal has been bent, let it cool slowly, so the crystals have time to reorganize and stay hard.
Bending Cold Metal
Sometimes, it is necessary to bend metal when heat is not available. In such cases, secure the metal before bending it. Follow the same procedure as bending hot metal, but omit the heating and cooling steps. If the material is brass, you may not want to bend it while it's cold at all; it can shatter or crack. Never bend any rod or rectangular bar of cold metal past a 60-degree angle. Anything more most likely will crack the metal. If you have a vise, use it to secure the metal, then use tongs to hold the metal and bend it. If you have an anvil, you can use its horn as a template and bend the metal around it.
Wear heavy gloves and eye protection when bending metal. Do not touch hot metal with your hands. Use only tongs or a vise. If you know how to quench (rapidly cool hot metal in cold water or oil) metal and feel it is necessary after heating it, you may want to use more protection. Quenching can cause metal to shatter. Know the type of metal you are using before heating it. Never heat metals that are galvanized or that have zinc in them--unless you have access to a respirator that is certified to filter out poisonous gases. A simple facemask is not sufficient to block zinc fumes, which will kill you.