The straight thread connection of reinforcement belongs to one method of mechanical connection. The straight thread is also divided into the following three methods.
(1) upsetting straight thread connection: it is the joint formed by the engagement of the straight thread made after upsetting the end of the steel bar and the thread of the connecting piece. The quality of the upsetting head is difficult to control.
(2) direct rolling straight thread connection: it is to put the ribbed steel bar into the rolling machine and roll it through the rolling wheel to form, with slightly poor thread accuracy and false thread.
(3) rib stripping and rolling straight thread connection: firstly, strip and cut the longitudinal and transverse ribs of the reinforcement joint to make the column diameter reach the same size before the reinforcement rolling, and then roll forming. It integrates rib stripping and rolling, with high precision of forming thread and long service life of thread rolling wheel. It is the mainstream technology of straight thread sleeve connection at present.