Fastening device for coupling of blades in agricultural cultivation machines, in particular, tilling machines such as rotary tillers, characterized in that it comprises an intermediate fastening element (1), formed by a solid body, which joins the blade (2) to the rotary plate (7) said intermediate fastening element (1) is equipped with fastening means (3) for linking same to the rotary plate (7) guiding means (4) for insertion of the blade (2) into the intermediate fastening element (1) and at least one through hole (5), extending transversely with respect to the direction of the guiding means (4) and intended for insertion of an extractable bolt (6) which, when said bolt (6) is inserted, acts as a retaining element for the blade (2) with respect to the intermediate fastening element (1). Said arrangement enables the user/operator to manually replace and/or reset the tilling blade, avoiding any need for accessory tools commonly used for this purpose.
