Piking servomotor from datasheet
kg, when used as part of the units for servo torque, always means 9.81N. 

kg is an incorrect but customary substitute for kgf, which is the force required to support 1kg in earth's nominal surface gravity. Even if the manufacturer did mean kg to represent mass, he actually means the force required to support that mass, that is kgf. It's the tension on a string that supports that mass.

When measuring torque, the units are always force × distance. It's customary for servo manufacturers to write that incorrectly as well. In context therefore, kg-cm does not mean mass minus cm, but means kgf × cm. Similarly kg/cm does not mean kg mass per cm, but kgf × cm. The correct way to write that unit would be kgf×cm.