Positive leg(KP leg) is universally known as NiCr10 or Chromel.
Negative leg( KN leg) is universally known as Alumel or NiAlCo/ NiSi3

Thermocouple wire Type K is supplied in the form of bare wire with dimension from 0.1mm to 6.0mm

For oxidised wires the available dimensions are 1 to 6mm.
Thermocouple wire can also be supplied in the form of stranded wire.

Products quality confirm to Standard

IEC 584-1/2/3
ANSI MC 96.1
ASTM E230
DIN EN 60584-1/2
NF EN 60584-1/2-NFC 42323-NFC 42324
UNI UNI-7938
JIS C1602-C 1610
GHOST 3044