The large variety of experimental information on M1 excitations in Th-
232 and U-236, U-238, obtained from (gamma, gamma'), (e,e') and (p,p')
experiments, is described in QRPA with a deformed Woods-Saxon potenti
al and separable residual interactions. The most accurate experimental
data on the low-energy orbital excitations, including their (e,e') fo
rm factors, are well reproduced. The influence of different parametriz
ations of the spin-orbit and spin-spin forces on the spin M1 strength
distribution is studied and the two maxima of this strength are interp
reted as isoscalar and isovector ones. The role of the spin-independen
t residual interaction for the promotion or suppression of the scissor
s mode is discussed. It is found that the scissors mode fragments main
ly (70%) over the low-lying orbital 1+ states and most of the stronges
t experimentally observed M1 excitations can be interpreted as perform
ing a weakly collective scissors motion.