Piercing, punching and blanking are three common machining processes that are used to manipulate raw metal, such as sheet metal. All three processes require the use of a machine, which in some way deforms or alters the physical properties of the raw metal. While similar, though, piercing, punching and blanking have different functions. Below, you’ll find an overview of each of machining process and how it works.
What Is Piercing?
Piercing is a shearing process in which raw metal is pierced with a machining tool, resulting in the creation of a circular or other shaped hole. As the raw metal is pierced, the metal from the newly created hole is considered scrap. The piercing machine forces a tool, known as a blanking punch, through the sheet metal.
There are several different piercing processes, some of which include the following:
- Lancing
- Trimming
- Notching
- Perforating
What Is Punching?
Punching is a machining process that involves the removal of scrap metal from a sheet of raw metal. It requires the use of a punch press to compress a tool through a sheet of raw metal. While punching is typically performed using sheet metal, it supports other materials like paper, plastic and various fibers. The punch press pressed through the sheet metal while placed against a die. Therefore, punched sheet metal takes the same shape as the die used.
What Is Blanking?
Blanking is often confused with piercing because both processes involve cutting holes into raw metal. However, they aren’t necessarily the same. With blanking, the metal from the hole is saved and used rather than discarded. In other words, manufacturing companies perform blanking to create small pieces of metal, whereas manufacturing companies perform piercing to create metal objects with a single hole.
The key thing to remember is that blanking results in the creation of multiple metal parts from a single piece of sheet metal. In comparison, both piercing and punching typically create a single hole in sheet metal.
As you can see, piercing, punching and blanking are three unique machining operations. They are all used to manipulate sheet metal, but each operation works in a different way. Piercing is used to create holes in raw metal by piercing it with a tool. Punching uses a machine to create metal objects in specific shapes using a die. Finally, blanking is machining process that’s used to create small pieces of metal.