The torsional oscillations of four single sunspots are investigated on the basis of the observations of the longitudinal magnetic fields and the velocity fields in the photospheric line Fe I λ 525.3 nm. We reconstructed all three components of the magnetic field and velocity field from their line-of-sight components. The period of the oscillations is from 3.4 to 7.7 days. The phase of the azimuthal component of the velocity is ahead of the phases of all three components of the magnetic field. If the density of plasma in the penumbra 10^-4 kg/m³, as the magnetic energy of oscillations exceeds their kinetic energy by a factor of 10 to 100. Our results indicate that those oscillations are not free oscillations.