Why do cables use lead as a sheath material?

The main reasons for using lead as the sheath material for cables are as follows:

Softness and processability: Lead is soft and has a low melting point, making it easy to smelt and process. This allows lead sheaths to have good plasticity during cable manufacturing, allowing them to meet the needs of cable sheaths of different specifications and shapes.

Chemical stability: Lead and its alloys have high chemical stability and are not easily corroded by acids, alkalis, and other chemical substances. This makes lead sheaths have good corrosion resistance during the use of cables, protecting the core wires inside the cables from external environmental erosion.

Sealing and moisture resistance: The lead sheath has good sealing and moisture resistance, which can effectively prevent moisture and humidity from entering the interior of the cable, thus protecting the core wire from the effects of a humid environment.

Mechanical strength: Although the mechanical strength of pure lead is relatively low, lead alloys have high mechanical strength and can meet the mechanical performance requirements of cable sheaths. Lead sheaths can resist external physical damage and tension, protecting the core wires inside the cable from external forces.

However, it should be noted that lead sheathed cables also have some disadvantages, such as the flexibility of lead may cause gaps in the cable when it expands under load and heat, affecting insulation performance. At the same time, lead is highly toxic and not conducive to environmental protection and human health. Therefore, with the development of technology and increased awareness of environmental protection, lead sheathed cables are gradually being replaced by other more environmentally friendly and superior materials.

In general, the main reasons for the application of lead sheath materials in cables are their flexibility, processability, chemical stability, sealing and moisture resistance, and mechanical strength. However, with the increasing environmental protection requirements and the development of new materials, the application of lead sheath cables is gradually decreasing.