spring balance
Scale made up of a hook attached to a spring that stretches in proportion to the weight of the object being weighed.
hook 
Curved part on which the body to be weighed is hung.
graduated scale 
The divisions of equal length that are marked on the spring balance and constitute the units of measurement.
pointer 
Pointer connected to the spring that moves along a graduated scale to indicate the weight of the body being weighed.
ring 
Round part for holding or hanging the spring balance.