The cold heading method is to use the plasticity of the metal and the cold state mechanics to apply pressure or cold drawing to achieve the purpose of solid-state deformation of the metal. The production of screws demands a series of tools including cold heading dies, header punch and KO pin, cutting die, and thread rolling die are needed to use.
The product we mainly introduce today is the second punch header, also called fine blanking header punch. It is widely used for stamping and slot forming of materials of screw fasteners such as self-tappers and wood screws in the hardware industry. The second punch plays an important role in the final head forming of screws, which is different from first punch. The function of the first punch, also called the preliminary punch, is the formation of a set of conical metals in the die, while the main task is to pre-fill it before the formation of the head. The application of second punch is a process afterward first punch, can be irregularly shaped which depending on the final screws’ usage the manufacturer demands.
In addition to the combination of SKH9 high speed steel with tungsten carbide material, the manufacturer of screw header punches applies an improved tool production technology by welding high-carbon high-chromium alloy steel SKD11 with high hardness to a carbide material (tungsten carbide). The tips of tungsten carbide punches are tensile tested, have a perfect polished surface, which significantly increases their wear resistance, increases tool life compared to punches made of conventional tool steel.
Precision and quality of tool manufacturing improves tool functionality, increases productivity and reduces tool changeover times. Excellent tool life creates added value and contributes to production savings. The screw header punches are capable of processing stainless steel products that have been pre-heat treated.
By design, there are different types of second punches, such as plum blossom punch, triangle punch, hexagonal punch, rice punch, etc. Those punches can meet the demand for production of different types’ production of the heads and slots. The slot is used to efficiently transmit torque and head pressure. Now a variety of types of slots are used. In addition to traditional types such as the cross slot or straight slot, other types become more and more popular including tri-Wing, four-wing, slot with internal hexagon and many others.
How to choose a good quality second punch?
First, look at gloss. Generally speaking, high-quality precision tungsten steel punches have a high gloss and without rust or spots, and have a certain degree of reflection.
Second, listen to the sound. The high-quality precision tungsten steel punch will make a crisp metal sound when it is lightly hit.
Finally, feel it with your hands. The quality of precision tungsten steel punches will be heavier, and the punches made of synthetic materials with lower quality are very light in weight.
The function of the screw second header punch is introduced here. I hope it will be helpful to you. Friends in need can contact us.