How can the external and internal electric irons be distinguished?
Outside heat type: the heating wire is outside the soldering iron head.Internal heating type: electric heating wire is in the inside of the iron head
As the name suggests, the heating wire of the external hot electric iron is outside the iron head.Internal heating is just the opposite.
The outer hot iron head is inserted in the round hole in the middle of the iron, and the heating part is in the outer ring; the root of the inner heating iron head is a hollow round sleeve, and is sheathed on the iron, and the heating part is in the inside of the iron head.
