1. The possible free rotation of standard connection. The reason for using steel bars is mutually opposite to the vertex force that locks the bridge piece. Would like to choose standard sleeve or reduced-diameter connecting sleeve.

　　2. The lengthened connection is used for occasions where the steel bars are too long and dense and inconvenient to rotate. The connecting sleeve is fully screwed into the elongated thread of a steel bar in advance, and then the end thread of the connected steel bar is screwed back in. The connecting piece can be locked by turning the steel bar half to one turn. A standard connecting sleeve can be used.

　　3. Locking female type connection is used for the mutual connection of steel bars that cannot rotate at all, such as bent steel bars and bridges, cast-in-place piles and other steel cages. Screw the lock nut and the connecting sleeve into the extended thread in advance, then screw in the thread of another steel bar end, and lock the connecting sleeve with the lock nut. Optional standard or flared connection sleeve plus lock nut

　　4. The positive and negative threaded connection is used for occasions where the steel bar cannot be rotated at all and the internal force of the steel bar needs to be adjusted, such as construction joints, post-pouring belts, etc. The connecting sleeve has positive and negative threaded fasteners. The two steel bars can be loosened or tightened in one rotation direction. The connecting sleeve with positive and negative threaded fasteners should be used first.

　　 Pay attention to the following nine points when making.

　　 1. When connecting steel bars, the specifications of the steel bars and the connection sleeves should be the same, and ensure that the steel bars and the connection sleeves are clean and intact.

　　 2. The steel bars should be straightened before cutting. The cut end face of the thread rolling machine should be perpendicular to the axis of the steel bar without horseshoe shape or bending. Do not use gas to cut the material.

　　3. The taper, tooth shape, and pitch of the processed steel tapered thread must be consistent with the taper, tooth shape, and pitch of the connecting sleeve, and have been tested by a matching gauge

　　Passed. The steel connecting sleeve processed by the automatic sleeve tapping machine produced by Henan Sangao Machinery fully meets the national standards. Easy to tighten and secure connection.

　　 4. When processing the taper threads of steel bars, aqueous cutting lubricants should be used.

　　 5. The thread ends that have passed the inspection should be protected.

　　6. When connecting steel bars, screw the steel bars into the connecting sleeve on the positive axis, and then tighten them with a torque wrench.

　　7. When using pre-embedded joints, the position, specification and quantity of the connecting sleeve should meet the design requirements. The steel bars with the connecting sleeve should be fixed firmly, and the exposed end of the connecting sleeve

　　 There should be a sealing cover.

　　 8. The joints must be tightened with a torque wrench with an accuracy of ±5%, and the torque wrench must be verified with a torque meter every six months.

　　 9. Operators must hold a certificate to work.