Heading machine is a metalworking process used to shape metal materials such as iron, aluminum, copper, brass and stainless steel into the desired shapes without any additional heat. This process, also called cold forming, is a very efficient and quality process that saves costs and materials in comparison to machining methods that cut the materials into their final shape. It is a highly specialized and time-consuming operation, and the most important factor for success in this type of manufacturing is using high quality raw materials.
The first step in the process is obtaining a coil of wire. This wire is purchased in a specific condition known as spherodized anneal, and this allows the material to be shaped without cracking or breaking. The coil of wire is then pulled through a draw box to change the stock diameter to the desired size required for the fastener being manufactured. A wire straightener is often added to the system as well, and this ensures that the final product will have an accurate size.
Once the coil of wire is ready, it is loaded into a cold heading machine. This is a highly specialized machine that will shape the wire into the required parts at very high speeds. The machines can handle a wide range of products, including core aluminum rivets and semi-hollow iron rivets. Before the coil of metal can be formed into a fastener, it must be placed into a die. The die will have a punch on the moving part, and the punch is small compared to the dies that experience much more loading. The punches are typically designed to create a specific shape for the fastener, and they can be used as support for trapped extrusions or recess pins that aid the backward extrusion of drive recesses in screws.
After the punch has created the desired shape, the die will be pushed up against the punch and the metal will be forced into it by the hammer that is used to perform the upsetting process. The hammer is controlled to only strike a certain amount of metal per stroke, and this is what determines how large or small a piece can be made. Engineers have found that only two percent of the material can be upended in one blow, so many parts are hammered into the die multiple times to achieve their desired shape.
The process of cold forming is much more cost effective than other manufacturing methods, such as screw machining. This is because more of the material can be utilized during the forming process and there is little waste, and it is also much faster, with most machines able to produce at speeds up to 100 pieces per minute. The final products will have tighter tolerances and require less finishing, which will help to reduce overall costs even more. This is why cold forming is growing in popularity for the production of fasteners and joints. This is especially true for industries that use large amounts of these components in their operations.