Tempering is another type of heat treatment that is used to strengthen a metal. The metal is heated to a temperature which removes internal stresses and any brittleness, but below its melting point. It is commonly used following quenching, in order to reduce any brittleness that may have occurred from the rapid cooling of the material.
Tempering is usually used on ferrous metals such as cast iron and steel and the temperatures used, as well as the time that the workpiece is subjected to that temperature, will vary depending on the material.
Tempering is commonly used to ensure the strength of load-bearing parts, such as those within construction applications. However, it requires the use of a furnace, meaning that it may have to be carried out by a specialist supplier.