Why is torque sometimes reported in kg m, instead of the usual N m? On various websites I see torque expressed as $\rm kg\: m$, but I was always thought that torque is $\rm N\:m$ or $\rm kg\: m^2/s^2$. These are clearly not the same, so why are they called the same, and when do I use one or the other?
 A: The non SI unit is often written as 1 kg-m and is equal to 9.8 N m.  
In such a case the 1 kg refers to the unit 1 kg force which is the weight of one kilogram.  
Another unit is the Imperial (and US) unit the pound-foot which is equal to approximately 1.36 N m.
Here the unit of force is the pound force.
A: Those other sources were probably referring to kilogram-force instead of Newtons. Given the constant conversion between mass and weight on Earth (i.e., $g = 9.8\,\textrm{m/s}^2$), mass and weight units are often used interchangeably in non-scientific contexts. So, torque can be expressed in kgf-m, where 1 kgf is the weight of 1 kg on Earth's surface. Notice that this is a multiplication, not a division. Units of kgf/m would be completely incorrect.
A: Well I think both of the Units are right. But its not kgm it should be kgf-m.
Torque means - - - >   F×R. ..
 Hence it has units of Force times distance.
N-m is one of the units where N is unit of Force and m is distance.. While in 
Kgf-m Kgf is unit of force and m is distance as Usual.
