Sheet metal fabrication is a well-established production process for making sheet metal parts. It involves the use of techniques such as bending, stamping, cutting, forming, etc. to create sheet metal. After the sheet metal part is produced, depending on the usage and other factors, the sheet metal part can undergo a post-processing stage through the application of sheet metal finishes.
Steel, aluminum, brass, copper, tin, nickel, titanium or other precious metals are traditionally used to make sheet metal. Thicknesses vary, but mostly fall into two distinctions; thin gauge and thick plate. Many different industries rely on sheet metal for its versatility and durability, including aerospace, appliance manufacturing, consumer electronics, industrial furniture, machinery, transportation, and more.
Why choose sheet metal?
Sheet metal offers many advantages over non-metal alternatives and other metal fabrication processes. Compared to machining, sheet metal is much cheaper in terms of machining and material cost. It doesn’t have the extremely high tooling cost of injection molding, which makes sense when it comes to high-volume production.
As found in machining, instead of starting with an expensive piece of material, much of which is wasted in the milling process to remove unwanted material, sheet metal allows you to buy the material you need and use relatively less material waste. The unused board can then be used for another project, while the shavings from processing need to be discarded and recycled.
As powerful as today’s engineering tools are, you can only know if a design is as expected when you can see and work with a part. Is it strong enough? Is it light enough? Does it look, feel and balance the way it should? Will it sacrifice other components? Even relatively simple components can benefit from practical trials before investing in hundreds or thousands of parts. In some cases, multiple prototype iterations may be required to get the sheet metal part right. With a good manufacturing supplier, the process
The overall project impact can be kept to a minimum, but done early in the prototyping process.
Large enterprises can easily outsource design to engineering service providers so they can focus on core activities. However, choosing the right partner can help avoid further widening the gap between the ideal design and manufacturing process and the very common real-world scenario of delivering a poor design to the manufacturing floor without addressing design flaws. When choosing a manufacturing supplier, look for companies with a proven track record in producing parts and extensive manufacturing knowledge to ensure fewer design issues during manufacturing and faster time-to-market.
Sheet Metal Manufacturing Technology
Cutting: Shearing is one of the oldest methods of cutting sheet metal, but has since been superseded by faster and more precise methods.
Punch: Using tools called punches and dies, holes and shapes can be punched to make any number of patterns. Particularly suitable for cutting simple patterns that are more economical than laser cutters or water jet cutting. Punch presses can operate at hundreds of strokes per minute, making them a suitable center for rapidly machining parts.
Laser Cutting: Uses a combination of oxygen, nitrogen, helium or carbon dioxide to burn off material and produce clean edges. This form of cutting can hold very tight tolerances.
Photochemical Machining: is the process of using a CAD-generated template to control etching to leave a pattern that is chemically activated to remove unwanted material.
Hemming: In this forming operation, the edge of a sheet of metal folds over itself or folds over another sheet of metal for a tight fit or a stronger rounded edge. Hemming is a technique that joins parts together, improves appearance or adds strength and reinforces the edges of parts. Two standard crimping processes include roll crimping and conventional die crimping. The hemming is carried out step by step by means of hemming rollers. An industrial robot guides the crimping rollers and forms the flange. Traditional mold hemming is suitable for mass production. Using a die hemming, use the hemming tool to fold the flange over its entire length.
Bending: Most sheet metal bending operations involve punch and die type setup when forming along one axis. Punch and die are available in a variety of geometries to achieve a variety of different shapes. Bending metal can achieve many different shapes, from long, gentle curves to tight angles at, below or above 90-degree angles. When sharp corners are required, a press brake is usually required. Rolling and forming methods are used when a long continuous radius in one direction or along one axis is required.
Standard Finish Options
If you buy a sheet metal part to test for form, fit, or function, you probably don’t care much about the overall appearance of the part, but you also don’t want it to have sharp edges or a rough surface to take the metal straight from the mill. To remove dross and burrs from laser cutting, we subject the parts to a process called deburring.
Sandblasting is a finishing process that involves the use of compressed air to blast thousands of tiny abrasive particles (like glass or sand) on the surface of a sheet metal part. The continuous impact of these tiny beads on metal surfaces results in a smooth sheet metal finish and a matte texture.
Sandblasting is a fairly standard sheet metal finishing process. However, it is also ideal for cleaning or removing paint from finished parts. The visual quality of sandblasted metal parts makes post-processing a popular choice for visual applications requiring a matte quality. Therefore, it is a common aluminum sheet metal finish that can be used for parts that require high visual quality. Other finishing processes can also be performed after sandblasting if desired, it is ideal for parts that require cosmetic properties
Anodizing is another sheet metal finishing solution for aluminum and titanium sheet metal parts. It is a technology that uses an electrochemical process to form a corrosion-resistant layer on the surface of sheet metal parts.
The process involves dipping the sheet metal part in an acidic electrolyte bath and exposing it to an electrical current. The combination of these elements results in the transformation of the surface of the sheet metal part into an anodized layer that is fully integrated into the surface of the part.
Anodizing can also impart a variety of surface finish colors. It is a common finishing process for the production of mechanical parts, aircraft and auto parts, precision instruments, and more.
Powder coating is an aesthetic finishing process that involves spraying powder coating onto the surface of a material. In sheet metal fabrication, the sheet metal is then baked to paint its surface. This creates a strong layer that is resistant to corrosion and wear. Therefore, powder coating is superior to more traditional painting methods because it creates a strong coating on the outside of the component.
Powder coatings are available in a variety of colors to suit customers’ aesthetic and branding requirements. It also offers various sheet metal finishes such as gloss, semi-gloss, flat, metallic and textured. Powder coating prices vary by color, finish, and part geometry.
This is another popular sheet metal finishing process in which a fine layer of another metal (sacrificial metal) is deposited on the surface of a sheet metal part. Electroplating is performed by placing the sacrificial metal in the anode position and the sheet metal part in the cathode position. Both metals are placed in an electrolyte similar to the anode material. The two metals are then bonded through conductive chemistry.
There are several options for plating materials, each offering a different combination of properties. At elimold, we can electroplate sheet metal parts using tin, nickel and electroless nickel. It is important to note that if plating is used, the tolerances of the original part should take into account the thickness of the final plating.
Electroplating increases electrical conductivity and increases the resistance of a part to radiation, so it is often used to produce radiation shields.
write at the end
Sheet metal finishing is an important part of sheet metal processing. They are important for many aesthetic or functional uses required in manufacturing. You can use many sheet metal finishing processes.