Wire Wound Resistors are made by wrapping what is known as resistance wire around an insulating core. Wires made of tungsten and manganin are commonly used for this purpose. Wire wound resistors are encased in an insulator such as ceramic. Usually Wire Wound resistors are used for high wattage applications, that is wattages greater than 2 watts. The resistors have a great tolerance for heat and are typically labelled flame proof.