High Temperature Wire Uses Bare Copper
High temperature wire products are based on the type of insulation that covers the copper strands not the copper itself. Basic lead wire insulation is PVC which is typically rated up to 105°C. When you upgrade to PTFE from PVC insulation it’s rated up to 200°C.
Bare Copper
Bare copper strands are used in both PVC and PTFE insulated wire because copper is a good conductor of electricity without costing an arm and a leg. Solid stranding will hold its form while stranded will be more flexible. Other than that, there isn’t much of a difference between the copper used in either type of wire.
Silver Plated Stranding
High temperature wire uses silver plated strands to help with corrosion in applications of higher temperatures. PVC lead wire uses Tin instead of silver because corrosion isn’t an issue. Using silver also increases the price compared to using tin but you cannot get PTFE high temperature wire without silver because it completes the package.
Insulation
PTFE is used as high temperature insulation up to 200°C and PVC is used for standard temperature applications up to 105°C. So, high temperature wire layers include bare copper, silver coating and PTFE insulation in order to create a wire rated to 200°C. Basic lead wire uses bare copper, tin coating and PVC insulation for a more cost effective wire.