What is punching?
PUNCHING
It is a drilling process that uses a press to force a tool, called a punch, which creates a hole by shearing. Punching is applicable to a wide variety of sheet-shaped materials, including various types of metals and plastics. In the process, the punch passes through a die, pushing and depositing the sheet material inside the die. The rest of the material remains in its original position, “remaining pierced”. Punching is usually the most economical method of piercing materials.
A similar process is embossing, a material deformation operation in which the punch is stopped as soon as the metal is deformed without being pierced.
THE TERM PUNCHING
The term punching comes from the Latin “punctio” meaning to prick. The origin of this term comes from the fact that the material, during its processing, is “pricked” by a tool called a “punch” that impresses a cut, a shape or a sign.
THE PUNCHING PROCESS
Punching tools are often made of hardened steel or tungsten carbide.
As mentioned, the punch passes through a die, pushing and depositing the sheet material into the die.
To prevent the punch from sticking to the die, a small amount of space is left between the two, resulting in less force being required to punch the hole. The amount of force required depends on the thickness and hardness of the material being punched, and the diameter of the hole being punched. Physics dictates that it is impossible to punch a hole with a diameter smaller than the thickness of the sheet, however, there are now some techniques for punching holes that are below the thickness.
So, this process creates a hole that is the same diameter as the punch, or slightly smaller after the punch is removed. All ductile materials stretch to some extent during punching, often causing the punch to stick to the material being punched. In this case, the punch must be physically pulled out of the hole. The waste material from the hole falls through the nut into a sort of container.
Punching is just one of four methods we use to drill materials, the others being laser cutting, water cutting and drilling.