Aircraft quality wire is manufactured to MIL-W-22759/16 specs. It features standard tin-plated copper conductor with Tefzel insulation.
18 gauge white wire.
18awg stranded white Tefzel (ETFE)insulated M22759/16-18 wire.
Wire is rated for 600volts rms & 150 degrees C.
FAA AC43.13-1B recommends 10 amp CB protection for 18awg wire.
See FAA AC 43.13-1B Tables 11-3 & 11-9 for protection & rating details.
See Military Specification Sheet MIL-W-22759-16a for wire construction details.