Piercing, punching, and blanking are techniques that play an essential role in sheet metal fabrication. All of them have specific features and uses. For instance, Piercing provides holes without removing any material. Punching produces sheet metal shapes. Blanking cuts individual pieces from one larger sheet.
Let’s examine each method in detail, focusing on its processes, benefits, and ideal usage cases. The knowledge you gain from this can help you in metal sheet fabrication projects.
Key Takeaways
- Sheet metal fabrication is a dynamic process that involves various shearing processes depending on industry requirements.
- It involves piercing, punching or blanking during the manufacturing process, depending on the end product.
- Each fabrication process involves different processing and different tool and dies.
- Sheet metal processes involve a variety of methods to cut thin metal sheets.
Understanding Piercing, Punching, and Blanking
What is Piercing?
Piercing is a metal fabrication process that create precise holes in sheet metal. The punch penetrates the material to create an opening, but it doesn’t remove any metal. It typically displaces the material while creating a small bulge around the hole’s edge.
The piercing operation works well for creating holes with high precision and small diameters in thin sheets and is, hence, widely used in the automotive and electronics industries.
What is Punching?
Sheet metal punching uses a punch press to cut specific shapes from sheet metal, creating predetermined forms. The removed piece, called a slug, is typically discarded as scrap metal. This method excels at quickly producing repeatable and consistent parts, making it ideal for high-volume production and mass manufacturing processes.
What is Blanking process?
Sheet Metal Blanking involves cutting a desired shape from a metal sheet. The cut-out piece serves as the final product, and the remaining sheet becomes waste. This process efficiently produces flat, uniform parts with clean edges, making it ideal for mass production of identical components.
The blanking process is common in automotive, aerospace, and appliance manufacturing to create large numbers of identical parts from sheet metal objects.
Key Differences: Piercing Vs. Punching Vs. Blanking process
Material Removal: Piercing vs Punching vs Blanking
Punching and blanking operations are quite different from piercing. Piercing does not remove any material from the sheet of metal. Instead, it only displaces metal, creating an opening that causes slight deformation around the edge of the hole.
Punching and blanking both involve cutting away material. The punching process cuts out the area around a cavity. This means that the piece removed is considered scrap metal. The hole left behind is the product that one wants.
Blanking, on the other hand, is the opposite of punching. In this case, the removed piece is taken as the desired product, while the remaining metal sheet is either discarded or recycled.
Hole Shape and Size: Piercing vs Punching vs Blanking
The piercing process produces relatively small, simple holes, which are usually round of the same shape or of any simple shape. The size range is limited compared with piercing or punching.
Punching process is much more versatile in shape and size. There are many more options available for forms, from circles to very complex shapes. The size range is potentially bigger than piercing, but the tooling limits can also limit it.
Blanking operation focuses on the cut-out piece rather than the hole. It’s an application that can punch very large shapes, often whole parts. The “hole” left behind is what is not wanted- the negative space of the desired product.
Tooling and Die Selection for Piercing, Punching, and Blanking
Piercing uses a simple punch without a matched die. The tool determines the shape of the hole. This is a very simple setup, and changes can be made quickly.
Punching requires a matched punch and die set. The punch pushes material through a die opening. This can give an extremely clean cut, with the expense of more time for setup.
Blanking also utilizes a punch-and-die system. However, the blanking die opening is comparatively larger to accommodate the finished product. The clearance between punch and die blanking tool must be substantial to achieve neat edges on the blank.
Custom sheet metal manufacturers guide industries in choosing appropriate die openings and blanking tools.
Force Application: Piercing, Punching, and Blanking
Piercing applies concentrated force to a small area. The punch applies pressure along the hole’s path. This focused force can pierce material effectively in a single operation.
Punching distributes the force over a larger area. It applies pressure along the whole outline of a desired shape, spreading the force for neat cutting of complex forms.
The blanking process requires a high shearing force of the three processes. It must pierce through the resistive forces of the material over the entire periphery of the raw metal blank while the force has to shear throughout the full thickness of the sheet.
The right material is selected based on the project’s specific requirements, including the desired shape sheet thickness, size, and properties, under guidance from the best contract manufacturers in India.
Speed and Precision: Comparison
Piercing has excellent speed and satisfactory accuracy for small diameters. It finds optimal use in mass-production operations, in which parts with small diameters often have to accommodate several simple holes.
Punching is an operation that balances, to a great extent, between speed and precision. Complex shapes could be struck quickly with few inaccuracies.
Blanking may be slower as a technique for large and complex profiles. However, blanking can achieve outstanding levels of precision for the finished part.
Material Strength and Durability Impact
In Piercing, the metal can be weakened on the sides surrounding the hole to some extent due to the material surrounding the hole. There is also displacement of the metal from the hole, hence there would be stress points. However, in the case of thin sheets, this effect tends to be minimal.
Punching can deform some sections of the edges around the hole, resulting in weakening material strength in that section.
Blanking is the process that has the slightest effect on material strength. The finished product’s structural integrity remains intact.
Sheet metal and stamped parts suppliers guide industries about the necessary fabrication processes depending on their end product requirements.
Conclusion
Piercing, punching, and blanking are crucial processes in sheet metal fabrication, and understanding the differences is essential for achieving precise and efficient operations. The processes offer several benefits, including high precision, dimensional accuracy, surface quality, and cost efficiency.
By following best practices and selecting the right tooling and die design, manufacturers can achieve precise and efficient Piercing, punching, and blanking operations. Piercing, punching, and fine blanking are widely used in various industries, including aerospace, automotive, electronics, and construction, and secondary operations are ideal for creating metal parts with specific shapes and sizes.
Frequently Asked Questions
Can piercing, punching, and blanking be done on the same machine?
Most new CNC machines do all three; however, the dedicated machines are mainly better. Your production needs and the capabilities of your equipment will determine the best alternative.
Which process is more suitable for thin materials?
All of them can process thin materials, but piercing is the best method for manufacturing thin sheets and small holes. It generally provides low distortion and the highest accuracy with fragile materials.
How do the costs of these processes compare?
Production costs based on components, speed, and material waste are the main factors. The initial process with the lowest costs is the one that usually uses piercing the most. However, high-volume jobs are best done with blanking. For small runs, punching or piercing are better cost-wise. On the one hand, speed for high-volume jobs will make the higher cost of blanking acceptable.
Aparna Sushumna
About the Author
Aparna Sushumna, a mother to a hyperactive toddler who is all over the house. I aspire to be a decent content developer. A Bachelorette of technology says my qualification but I anticipated being a singer. Thanks to the recession, I dwelled into various jobs, from coding to being a tech support executive to a help desk professional, only to conclude that there is something else I wish to do. Here I am to accomplish my profound passion for content writing. Music, nature, jewelry, beauty, mythology, life quotes, celebs, and their life, being my areas of interest.