The gram-force and kilogram-force were never well-defined units until the CGPM adopted a standard acceleration of gravity of 9.80665 m/s2 for this purpose in 1901,[5] though they had been used in low-precision measurements of force before that time.
Even then, the proposal to define kilogram-force as a standard unit of force was explicitly rejected.
They are still in use for some purposes; for example, they are used to specify tension of bicycle spokes,[9] draw weight of bows in archery, and tensile strength of electronics bond wire,[10] for informal references to pressure (as the technically incorrect kilogram per square centimetre, omitting -force, the kilogram-force per square centimetre being the technical atmosphere, the value of which is very near those of both the bar and the standard atmosphere), and to define the "metric horsepower" (PS) as 75 metre-kiloponds per second.
[3] In addition, the kilogram force was the standard unit used for Vickers hardness testing.
The decanewton or dekanewton (daN), exactly 10 N, is used in some fields as an approximation to the kilogram-force, because it is close to the 9.80665 N of 1 kgf.