Thread Rolling
Thread rolling is a metal forming process used extensively in fastener, automotive and other manufacturing applications. It is used instead of cutting, dieing and knurling because of its high production rate, dimensional accuracy and cost savings. Threaded rolling is a cold forming process, and can be used with all types of materials, including aluminum, brass, copper, stainless steel and titanium.
Thread rolling is the process of forming threads on a rod, wire or other workpiece by placing the workpiece between two, three or four dies, which contain grooves that form the threads. The dies are held together by powerful, hydraulically actuated two-piece clamps and are then rolled under tremendous pressure. The pressure from the clamps forces the dies to conform to the shape of the thread to be formed on the workpiece. As the dies rotate, the threads are rolled into the installed material and in a single operation, threads are formed with a cutting or swaging action.
Thread rolling produces threads that are stronger, more accurate and fatigue resistant than threads produced by cutting, dieing, or knurling. The cold forming process increases the strength of the workpiece, as the material is redeveloped during the thread rolling process. Because less material is removed, tolerance control is improved and machining and grinding time is reduced. Thread rolling machines have a higher speed of operation than dieing and thread cutting and because the machines operate at lower speeds, there is less chance of wearing out the forming dies.
When designing a game that includes threaded rolling, the designer must make sure they use the right type of dies to form the threads on the workpiece. The types of dies used depends on the type of material being worked with and the size of the thread. For example, when threading steel, a rolling die can be used that has induction hardened teeth, which will help increase the yield strength of the thread. Rolling dies are also available with a core or no core, as well as a comprehensive range of tapering and finishing after-forming dies.
When rolling stainless steel, it is important that the formed workpiece has a high level of corrosion resistance. To achieve this, after rolling is complete, a lubricant oil is applied to the workpiece to protect it from oxidation and to prevent the formation of rust.
The thread rolling process is highly efficient and a cost-effective way to form threads on rods, wires and other materials. It requires minimal machining and grinding time, creates threads that are stronger and more accurate than those created with other methods and increases the overall strength of the workpiece. When designing components that need threaded rolling, it is important to select the right type of dies and lubricants to ensure the highest possible quality.
