For the moment of force (torsional moment) the coherent derived unit in the SI System is N · m (newton metre).
A derived unit often used is kN · m (kilonewton metre). The symbol for kilonewton correctly has to be written "kN" ("KN" and "Kn" are wrong!).
k = kilo means the thousendfold of a unit (1 kg = 1000 g; 1 km = 1000 m; ...)
K = kelvin means the unit of the thermodynamic temperature
N = newton means the unit of the force
n means the number of molecules or similar