Self-locking steel nail

The invention discloses a self-locking steel nail, and mainly relates to a steel nail used for connecting parts in woodware product processing. The self-locking steel nail is suitable for occasions where tools such as an iron hammer and a pneumatic hammer are used. At present, known steel nails all adopt structures of which one ends are acute-angle square cones, the other ends are cap-shaped flatbodies and the middle parts are cylindrical, and due to the limitation of clamping force of wood, such steel nail has the defects that the material cost and the man-hour cost are increased in a designed product and the like; in order to overcome the defects, the self-locking steel nail provided by the invention is characterized in that in a part steel nail main body, one end is an acute-angle square cone, and a groove is formed in the cylindrical body at the transition position of the acute-angle square cone and the cylindrical body in the middle of the steel nail main body, and the other endis a nail-cap-shaped flat