The temperature of the tool, which is converted from electric energy to thermal energy, is determined by its own power and the duration of the energization time. The large wattage is energized for a long time and the temperature is raised rapidly, while the temperature is slow and the temperature is low. Iron heating element, a mica skeleton heating element and the metal tube heating element two. Mica skeleton heating element made of iron, simple structure, easy to manufacture, more uniform heat, easy maintenance, the disadvantage is that the heating wire exposed to the air, oxidation at high temperatures fast, short life, susceptible to damp air, the insulation properties Poor. Electric iron pipe made of metal heating element mechanical strength, long life, high thermal efficiency, good moisture resistance, safe and reliable, but the manufacturing process is more complicated.