We use the empirical evidence that F-spin multiplets exist in nuclei for on
ly selected states as an indication that F spin can be regarded as a partia
l symmetry. We show that there is a class of non-F-scalar IBM-2 Hamiltonian
s with partial F-spin symmetry, which reproduce the known systematics of co
llective bands in nuclei. These Hamiltonians predict that the scissors stat
es have good F-spin and form F-spin multiplets, which is supported by the e
xisting data.