Optical cable steel wire is the "invisible guard" that ensures the stable transmission of communication optical cables. It is mainly used as the reinforcing core of optical cables to provide mechanical support and protection for fragile optical fibers. The most common variety is carbon steel with a zinc coating. In order to ensure that the cable can withstand enough axial tension when laying and applying, the cable must contain elements that can bear the load, metal, non-metal, in the use of high-strength steel wire as a strengthening part, so that the cable has excellent side pressure resistance, impact. Lead dust may be released into the manhole atmosphere any time the sheath of older lead sheath cable is disturbed. When working in manholes, precautions must be taken to limit the amount of exposure to lead.