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Heading machine is a metal forming process used to create intricately designed fasteners. This process uses high speed automated “cold-headers” or “part formers.”
A length of wire is fed into the machine, where a hammer upsets or extrudes the material into various shapes without heat. The result is a very precise part.
The Process
Heading is a metal forming process that drives the ends of a wire into a shape. It is a very efficient alternative to machining and can produce complex fasteners without secondary operations. It starts with a slug cut from a progressive coil or a blank strip of metal. The slug is then fed into the machine and it is driven into the die using a series of strong punches.
The machine is controlled by a set of rules that limit the amount of material that can be upset in one blow under controlled conditions. This is why single-die, double-stroke heading machines are commonly used.
Solid-die heading machines can also perform a combination of upsetting and extrusion, which allows them to make more complicated shapes than those possible on a traditional automatic screw machine. This type of upsetting is limited by the maximum shear reduction and shank length. It is typically performed before open or trapped extrusion.
Tooling
Cold heading machines use standard and custom tooling to perform a variety of sequences of cold forming operations. These operations include upsetting and extruding. They also can involve piercing, pointing, trimming and other processes. These cold forming operations can take place in a single die station or a multi-station type of machine.
During the process, the metal blank, or slug, is struck by a series of punches and dies. This process requires a great deal of skill from the machine setup technician to time correctly. The punches and dies are designed to a very precise specification for the specific fastener that is to be made.
Increasing metallurgical knowledge has enabled the heading of tougher materials such as high-temperature alloys and stainless steels. This makes the use of header equipment more economical. Moreover, the ability to combine upsetting and extruding in a single operation (called blows) has enabled larger head, smaller shank parts to be made on heading machines.
Material
Heading is a form of metal forming that occurs at room temperature, as opposed to traditional machining methods that use heat. This allows for more complex shapes to be made with fewer operations, and also results in a faster production time.
The process begins with a piece of wire or blank material that is fed through the header. Then, each punch of the machine performs one of several deformation techniques to transform the raw material into a fastener or other finished product. This includes upsetting, coining, extrusion, and bending.
Brass is an alloy of copper (Cu) and zinc (Zn). It has good processability for heading, and offers a balance between strength and toughness. This makes it ideal for applications such as anchor bolts, sheet metal screws, and door hinges. Moreover, it has excellent corrosion resistance. Besides, it is lightweight and offers greater resistance to wear and tear than iron. This makes it a popular choice for construction projects.
Final Product
Heading (cold forming) machines produce headed parts which are used in a variety of products including bolts, screws, rivets, taper roller heading, and pressure sensors. The process utilizes progressive dies and a series of powerful hammers to form the metal into the final product. This produces the finished piece with little to no waste, offers material cost savings, and creates stronger pieces while maintaining grain flow.
Cold headed fasteners require less machining than those produced with other methods. The process requires less energy than hot forging and is capable of producing more intricately shaped pieces.
It is important for manufacturers to consider the standards and requirements of their intended application when designing a part for cold heading. Choosing the right materials and design factors ensures that the finished part can be seamlessly integrated into the intended application. This also includes ensuring that the pieces comply with industry regulations for quality and safety.