Machining Small Metal Parts: Best Practices & Processes
During the metal stamping process, a piece of sheet metal is shaped into a 3D part (or multiple) using a metal stamping press. Throughout this process, the part is designed, material and tools are selected, and the part undergoes one or more machining processes to achieve the desired shape and design.
Once the sheet metal part is machined, it will go through one of the final steps in the metal stamping process – finishing.
In this article, we’ll define sheet metal finishing, discuss why it’s such a crucial part of the manufacturing process, and lay out your sheet metal finishing options.
What is Sheet Metal Finishing?
Sheet metal finishing is a key part of post-processing in the metal stamping process. Once a part comes out of the stamping press, finishing is where the final touches happen, whether that’s adding a protective coating, making additional cuts, or bending the part to fine-tune its shape and appearance. The exact steps depend on the part design and the stamping tools used, but the goal is always the same: a finished piece that’s ready to perform and look the part.
The finishing process is not only essential for aesthetic reasons, like eliminating burrs or marks, but it’s also crucial for protective reasons in some cases. Some sheet metal finishes are designed for improved corrosion resistance, or improved resistance to extreme temperatures, amongst other elements. The type of sheet metal finish you choose will rely on the component’s overall purpose.
The Benefits of Applying Finishing to Sheet Metal
Applying sheet metal finishing isn’t always required, but it does have a number of benefits to consider:
- Strengthens durability: If a metal component is going through a certain degree of wear, applying sheet metal finishing can increase its overall durability and wear resistance.
- Enhances overall appearance: If your sheet metal stamping design isn’t complete with the raw sheet metal, adding finishing can enhance the color or overall appearance of a part. It’s also possible that there are visible marks on the part as a result of the stamping process that need to be hidden, which is where finishing can come in handy.
- Reduces risk of corrosion: Parts that will be exposed to extreme temperatures or harsh chemicals will especially benefit from sheet metal finishing.
Options for Sheet Metal Finishes
While raw or rough finishing is an option, there are plenty of sheet metal finishing options available to you, depending on the material choice for stamping. Let’s take a look at some popular techniques:
|
Type of Sheet Metal Finishing |
Process |
Notable Benefits |
Applications |
|
Abrasive Blasting |
High-velocity stream of abrasive beads creating a non-reflective finish |
Finishing and cleaning |
Manufacturing, aerospace, automotive |
|
Anodizing |
Electrochemical process that transforms the surface to oxide |
Corrosion resistance |
Aerospace, automotive, construction, electronics |
|
Bead Blasting |
High-velocity stream of glass/plastic beads or sand, creating a matte finish |
Pre-finishing surface preparation |
Manufacturing, automotive, aerospace, medical, food and beverage |
|
Buff Polishing |
Rotation of low-abrasive, cloth-like material for a reflective, shiny finish |
Aesthetics |
Automotive, consumer goods, aerospace, |
|
E-coating (electrophoretic painting) |
Submersion of a conductive workpiece into an electrolyte solution |
Corrosion resistance for conductive, complex shapes |
Household appliances, automotive, electrical, aerospace |
|
Electroplating |
Electrodeposition process that coats a workpiece in a layer of metals |
Durability, conductivity |
Electronics, jewelry, automotive, medical aerospace |
|
Galvanizing |
Submersion of steel into molten zinc |
Durability, corrosion resistance |
Construction, automotive, agriculture |
|
Powder Coating |
Electrostatic coating of a substrate in a powder, which is then heated or cured under UV light |
Durability, corrosion resistance |
Automotive, appliances, exterior equipment |
Keep in mind this list is only a glimpse into the most popular types of sheet metal finishing. Not only are there other techniques with similar applications and benefits, but there are also variations of some of the methods above.
Read this article for more information on the ways metal stamping is used in some key industries mentioned above.
How to Choose the Right Sheet Metal Surface Finish for Your Project
It’s evident that your options for sheet metal finishing are plentiful. Each method has its own benefits and applications worth considering, depending on the type of metal you’re working with.
Consider how your part will be used and the elements it will be exposed to, and compare it to the chart above to get an idea of what route to take. Work with your manufacturer who can help point you toward the right finishing technique for your project.
Contact an expert today to get started on your stamping project and explore the best sheet metal finish for you.
