The Difference Between Metal Punching and Shearing in Metal Fabrication

In any kind of metal fabrication, there is a multitude of different ways to achieve the desired outcome.  Understanding how these different processes work, their different applications, and the tools needed are paramount if your next project is going to be a success.

Two of the processes that are easy to get confused about are punching and shearing.  Some people even think they’re the same thing.

In an effort to clear up some of the confusion, let’s have a closer look at each process specifically.

What is Metal Punching?

From 30,000 feet, metal punching really isn’t much more than taking a sheet of metal and punching holes in it.  While this is certainly true to an extent, the process and understanding it is a lot more involved.

During the punching process, specifically designed turrets on a punch press hit a sheet of metal either into or through a die to create holes.  These holes are often used for reasons of fastening.  Shaped pieces called blanking, are also used for practical or decorative purposes.

Different Types of Punch Presses

There are a host of different punch presses that each serve a specific purpose.  Let’s have a look at the two most common ones.

Hand-Powered Punch Presses

Hand-powered punch presses are most commonly used in light metalwork.  These devices are simple to operate and can be mounted on a workbench.  They also come with interchangeable die sets allowing you to customize your punches to your specific project.

Hand-powered presses are ideal for residential or fun, decorative undertakings.  They’re also considerably cheaper than industrial presses.

CNC-Controlled Punch Presses

CNC-controlled punch presses are operated by machine.

The process starts by the CNC controller moving the table along both an X and Y axis to a predetermined position.  Then the punching sequence is initiated.  Once the sequence is complete, the excess pieces (slugs) are ejected through the die and collected in a scrap container.

CNC-controlled presses are advantageous for their ability to create precise punches and the speed with which they can be operated.  For high-level production, a single cycle often only takes a few milliseconds.

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Shearing

Unlike punching, which penetrates metal all the way through, shearing trims excess material from sheet metal.

The process involves the use of tools, like a bench shear, to slice through metal with the utmost precision.  To begin, a piece of sheet metal is placed in between two blades.  Once secured using the tool’s squaring arm, the top blade slices through the metal pressing it into the lower blade.  The result is a clean, precise cut.

Shearing is also advantageous because it doesn’t involve the use of heat, and doesn’t produce waste in the form of chips.  Additionally, it’s incredibly fast making it ideal for high output projects and applications.  Lastly, the shearing process can be performed with almost all types of metal including stainless steel, aluminum, copper, iron, and bronze.

Final Thoughts

There are a number of reasons why you might want to use either stamping or shearing in your next metal fabrication project.  The key is knowing the difference between the two processes, and when it’s appropriate to employ each one.

If you’re curious to learn more about stamping or shearing or, have any other questions about your metal fabrication projects, give us a call at Meta Fab.  Our experts are standing by and eager to help in any way they can.