3. Huck riveting: using Hooke's law, after the fusion part is clamped with the special equipment of the core pulling rivet, the metal material of the ring sleeve is extruded and filled into the concave groove of the bolt column containing several annular pipe grooves, so that the ring sleeve and the bolt column are tightly integrated. Advantages: high clamping, good anti vibration and anti fatigue properties, high working efficiency of all iron double drum core pulling rivets. Defects: the bolt is longer and heavier, the production and manufacturing difficulty coefficient and price relativity, the traditional bolt riveting is more expensive, the key is suitable for the field with high added value and high load regulations. Huck standard part is a standard part which does not use torque to cause tightening force. The size of tightening force depends on the diameter of extruder screw and the matching ring sleeve. Super heavy and light trucks are widely used. 4. Zinc alloy bolt rotation method: using the basic principle of low melting point and friction heat generation of the raw materials of the rivet, friction is made between each other when the bolt rotates to drill into the plate, which makes the raw material part warm and soft, improves the plastic deformation, and produces the pier head, so as to achieve the riveting goal. Advantages: there is no need to drill holes before riveting, the relative processing technology is simple, and the actual operation is convenient. Riveted products are beautiful and elegant, low labor efficiency and high production and manufacturing efficiency. Defects: the production and manufacture of bolts are expensive, and the refrigeration factor should be considered in the whole process of riveting.