Thread rolling with cylindrical thread rolling dies and flat thread rolling dies are two different processes for producing threads.
Flat die thread rolling uses two dies with staggered thread teeth, with the stationary die fixed in place and the moving die moving back and forth in a parallel motion to the stationary die. When the workpiece is fed between the two dies, the moving die advances to deform the workpiece surface plastically and form the thread. Flat die thread rolling is suitable for producing external threads for standard fasteners and other threaded connections in large quantities.
On the other hand, thread rolling with cylindrical thread rolling dies can be divided into three forms: axial thread rolling, tangential thread rolling, and radial thread rolling. Axial thread rolling starts from the tailstock end of the turning center and moves along the centerline of the workpiece blank, forming the thread. Tangential thread rolling forms a thread by approaching the workpiece blank from the side, and radial thread rolling forms a thread with two or three rollers during one rotation of the workpiece blank. The working range of these thread rolling methods differs, and the length of the thread cannot exceed the width of the thread rolling dies.
Each method has its advantages and is suitable for different applications. Flat die thread rolling is efficient for producing large quantities of external threads for standard fasteners and other threaded connections, while thread rolling with cylindrical thread rolling dies is a more versatile process that can produce a wider range of thread sizes and shapes.