  A precise characterization of the magnetic properties of LISA Pathfinder free
falling test-masses is of special interest for future gravitational wave
observatory in space. Magnetic forces have an important impact on the
instrument sensitivity in the low frequency regime below the millihertz. In
this paper we report on the magnetic injection experiments performed throughout
LISA Pathfinder operations. We show how these experiments allowed a high
precision estimate of the instrument magnetic parameters. The remanent magnetic
moment was found to have a modulus of $(0.245\pm0.081)\,\rm{nAm}^2$, the
x-component of the background magnetic field within the test masses position
was measured to be $(414 \pm 74)$ nT and its gradient had a value of $(-7.4\pm
2.1)\,\mu$T/m. Finally, we also measured the test mass magnetic susceptibility
to be $(-3.35\pm0.15)\times$10$^{-5}$ in the low frequency regime. All results
are in agreement with on-ground estimates.
