Common materials (conductors) include:
1. Copper clad steel
This type of wire is relatively hard and not suitable for external pulling, as it is prone to core breakage. But it can still be used if buried in the wall. And can only be used for close range use, such as corridor junction boxes to users
2. Copper clad aluminum
This type of wire is relatively soft and prone to core breakage. It can be buried inside the wall or pulled outside the wall. And can only be used for close range use, such as corridor junction boxes to users
3. All copper.
This type of wire is soft and can be buried inside the wall or pulled outside the wall. It can be used for long-distance transmission.
Among them, the only ones that meet the national standards are telephone lines made of all copper