In building lead materials, in addition to the use of lead plate, pipe, solder, there are also lead mesh for plugging; A considerable part of the above lead tin solders, as low melting point fusible alloys (alloys of lead and tin, bismuth, cadmium, indium, etc.), are almost all wire materials. The lowest melting point of the latter is below 100 ℃, which is used for automatic arc extinguishing, electric fuse, boiler plug, etc.