Cold Heading
Overview of Cold Heading
Cold heading forms metal at room temperature under high pressure. The process strengthens the material, produces precise shapes, and requires little secondary machining, making it well suited to high-quality parts at low cost.The process is performed mainly on horizontal multi-station forging machines known as formers.
Features of Cold Heading
Formers have the following characteristics:
- Built-in cutoff and transfer mechanisms allow fully automated, continuous operation from wire feed to the final station
- High-speed production of tens to hundreds of parts per minute
- Continuous automated production keeps dimensional variation low
The Cold Heading Process
A typical cold heading sequence is as follows:
- Material preparation: Wire specially prepared for cold heading, such as SWCH-grade steel, is made ready.
- Cutoff: The wire is cut to the required length.
- Transfer into the die: The cut blank is transferred into the die.
- Forming: Under high pressure inside the die, the blank is shaped by operations such as:
- Extrusion
- Upsetting
- Piercing
- Finishing: Finishing operations are performed as required.
Advantages of Cold Heading
- Minimal material loss: Very little material is wasted, which keeps costs down.
- High precision: Because there is no heat distortion, high dimensional accuracy is achieved.
- High strength: The grain structure is refined and a continuous grain flow is formed, increasing the strength of the part.
- High-speed production: Fast cycle times and high productivity make the process ideal for volume production.
- Surface quality: The surface finish is excellent, and additional finishing is often unnecessary.
Limitations of Cold Heading
- Initial cost: Dies must be made, so there is an initial tooling cost.
- Setup: Setting up and adjusting the machine takes a certain amount of time.
- Not suited to small lots: Because dies are required, the process is not well suited to small quantities.
Typical Applications of Cold Heading (industry-wide)
Cold heading is widely used for automotive parts, fasteners, and other industrial parts made in volume. As demands grow for higher precision, more complex shapes, labor saving, and unattended operation, production methods that make the most of the former's capabilities are becoming increasingly important.
Cold heading is an essential technology for producing high-quality parts efficiently and in volume. Its defining strength is the ability to produce parts that are both precise and strong while making full use of the material's properties.