Among the various ways of steel bar connection in the construction industry, mechanical connection has rapidly developed with the advantages of energy saving, material saving, stable quality, and strong construction adaptability. In particular, the rolling straight threaded steel bar connection technology has become the main form of mechanical connection of steel bars. This technology is to process the ends of the steel bars into straight threads using a rolling process. After the two wire ends of the connected steel bars are screwed into the steel sleeve and are topped in the middle of the sleeve, the connection of the stressed steel bars is realized. After the force is applied, the force transition can be realized through the interlocking threads between the wire head and the sleeve, and finally the tensile force transmission between the two stressed steel bars can be realized through the connecting sleeve. It can be seen that the quality of the sleeve directly affects the construction site Rebar connection quality. Only qualified steel bars, without qualified connecting sleeves, still cannot fundamentally solve the quality, safety and stability of steel connection.

   The function of the rolling straight thread connecting sleeve is to transfer the force in one steel bar to another steel bar, permanently ensuring the uninterrupted transmission of tensile force, so that it can ensure that the steel bar reaches the same strength in the building force system, so the steel bar is connected The quality of the sleeve is the most critical, and the mechanical properties of the sleeve (strength, ductility, stiffness, fatigue performance, durability, construction adaptability and quality stability) must be ensured to ensure the quality of the steel connection.