Heading is a metalworking process that forms coiled wire into pre-designed shapes or components for the manufacturing industry. It can be used to create bolts, screws, rivets and other fasteners as well as a variety of other components that are used in everyday life. This process is very similar to machining, but unlike machining it is done without heat and the finished product can have much closer tolerances. It can also be performed at much higher speeds than machining and it is possible to forge parts from harder metals such as titanium and super alloys.
The cold heading machine produces a metal blank into a shaped or designed component by using a reciprocating ram to force a punch through a die. This can be a single or multi-die system and is usually used to create a complex design that requires multiple steps. The punches can be of different sizes and they can be used to pierce or trim the piece after it has been formed. In many cases this will not be necessary, but it is a process that can be used to improve the quality of the end product.
Throughout the heading machine processes it is possible to forge and shape a wide range of metals, but the process is most commonly used with materials such as stainless steel, aluminum, copper and brass. It is also possible to form parts from more exotic materials like titanium and super alloys by using a process known as hot forging, although this requires greater skill and knowledge of the material. The main advantages of cold forming are that it is much faster than machining and there is less waste as more of the raw material is utilized during the forming process.
Before heading is initiated, it is important to ensure that the raw material has been properly annealed and prepared. The process of forming can cause the material to crack or break if it is not annealed correctly and if the length to diameter ratio is too large. In order to prevent this, it is usually a good idea to use a draw box which will reduce the size of the stock before it goes into the heading machine.
As the material is hammered into the dies it can be shaped into many different designs and can even be threaded. This is especially useful for items that require internal drive recesses such as nuts, washers and bolts. It is important to remember that there is a limit to how much material can be squeezed at one time before it begins to fracture or burst, and this means that most bolt heads and screws will need to be hit several times in order to achieve their final size.
Another way that cold forming can be used is to increase the thickness of the part by rolling. This is a quick and economical process that can be used to make threaded components. This is an alternative to using a lathe or CNC machine and can produce components with much closer tolerances than a screw machined from raw metal. It is also more environmentally friendly than machining as there is no cutting involved and the piece does not need to be cooled down before it can be used.
