Using thin crystals of (TMTSF)(2)AsF6 the threshold electric field (E-
T) for the spin density wave (SDW) depinning was determined. At 4.2K,
E-T increases with decreasing cross-sectional area and it is as large
as 100 mV/cm in the thinnest sample studied. It increases with tempera
ture very weakly up to the transition temperature, in contrast with th
icker ones in which E-T decreases strongly with temperature.