When speaking of the tungsten carbide punches, we may think why the punches need to be made of tungsten carbide material.
Tungsten carbide is a kind of hard metal that the HRA is around 87~95. It is also called cemented carbide or WC. Or can be called “Black steel”, as its color is blacker than the color of normal stainless steel.
Then speaking of the punches, the punches here refer to the die punches used for metal stamping dies or called metal stamping punching tools. Metal stamping tools are used to produce metal parts in bulk quantities.
As a set of stamping tools and dies includes many parts and components, they are rough as below:
- punches and dies sets,
- positioning parts (guide plate, side pressure plate, location pins, distance blocks),
- Guide Parts (guide pins and bushings, guide plate),
- Supporting parts (Upper tool base, lower tool base, fixed plate, base plate, tool handle, spring),
- fastening parts (Bolt, screw, round pin),
- press plate and discharge plate.
Punches and die inserts as the main workpieces, need to undertake more pressure and impact force in the metal stamping tool working punching process. They are easy to wear and damage and a higher hardness could help prolong the punches’ lifetime and help ensure the stable quality of sheet metal stamping parts in the bulk production process.
That’s why the punch with a higher hardness is better.
There are different kinds of materials with different hardness:
- Normal Stainless Steel: HRC 56~60;
- High-Speed Steel (HSS): HRC 62~65;
- Powder High-speed Steel (PHSS): HRC 65~68
- Tungsten Carbide (WC): HRA 87~95;
According to different steel grades, we know that tungsten carbide is the hardest metal. So tungsten carbide is the ideal material for making stamping die punches.
Tungsten carbide punches can be briefly called carbide punches, or hard metal punches.
There is a problem, hard metal as its name is very hard and different to cut and process.
So how to process and machine the hard metal?
There are some different machining technologies that can do it. The first choice is grinding technology. There are various kinds of grinding methods, CNC Profile Grinding, CNC Cylindrical Grinding, and Plane Surface Grinding. With these grinding machines and sophisticated operation technicians, we can cut and machine the tungsten carbide hard metal and make the high-precision carbide punches with a tolerance of +/-0.001mm.
There are also some other machining methods, like Wire EDM and die-sinking EDM. An electrical spark is created between an electrode and a workpiece, the electric spark produces intense heat and will melt a precisely localized area on the surface of the workpiece. With wire-cut erosion or sinking erosion, we can also machine the tungsten carbide punches with high-precision requirements.
Whether grinding technology or EDM technology, it costs more for the machining of tungsten carbide than for the machining of normal steel materials.
The tungsten carbide materials cost is higher, and the machining tungsten carbide parts cost is also higher. So tungsten carbide punches’ cost is much higher than normal steel punches. But for stable and durable production of the metal stamping process, tungsten carbide punches are the best choice.
So if you are doing metal stamping, especially micro metal stamping, go to find a carbide punches manufacturer like us and use the tungsten carbide punches for metal stamping tools. It will enhance the working life of metal stamping tools twice than using normal steel and can make more stable quality metal stamping parts in bulk production.