The present invention relates to a fastening device (100) for fastening a railwayrail (10) onto a support (4), comprising a primary element (101) and a secondary element (102). The secondary element (102) corresponds to nut and bolt fasteners comprising at least one nut and one screw (9) with a screw body (82) and a screw head. The primary element (101) comprises at least one part (1,2) with an upper surface and lower surface, said part being crossed in its thickness by at least one aperture (80) able to receive said screw (9). Said aperture (80) is formed by a first recess (8) located on the upper surface of said part and intended for receiving the screw body and a second recess (8) located on the lower surface of said part and intended for receiving the screw head. According to the invention, the upper surface of the lower part is inclined according to a first slope (12) and the lower surface of the upper part is inclined according to a second slope (14), the first slope and the second slope being complementary. According to the invention, the upper part comprises means (81) for tilting the screw, said means located on the edges of the first recess.