Sheet metal manufacturing process

If you are considering starting a sheet metal fabrication process, you need to understand the fundamentals. This will provide a great starting point for you to make the most appropriate decisions. This article will cover the basic sheet metal manufacturing process to create a finished product or part.

1. What is sheet metal manufacturing?

• Sheet metal manufacturing refers to turning flat metal sheets into shapes and structures. Rather than viewing it as a single process, sheet metal processing methods involve using a set of forming techniques, working in parallel, and producing the required part. Sheet metal manufacturing is widely used in the automotive, aerospace and construction industries.
• Sheet metal manufacturing is done with many types of metals.

- Stainless Steel: Used for its durability and corrosion resistance
- Cold rolled and hot rolled steel: Both types are easy to shape, but cold rolled has a smoother surface and tighter dimensional tolerances
- Aluminum: A lightweight metal with an exceptional strength-to-weight ratio
- Copper and brass: These metals are easy to work with and look good when made

Your choice of metal will be determined by the end product and expected results.

2. What are the steps in the basic sheet metal manufacturing process?

After the engineering department creates drawings that turn flat metal sheets into functional three-dimensional products, the sheet metal manufacturing process begins, including the following steps:

2.1. Sheet metal cutting

The cutting process can be difficult, depending on the material and cutting method. For example, stainless steel is difficult to cut with a saw blade but is easy to cut with laser or waterjet cutting. The main cutting processes include:

• Plasma cutting
• Laser cutting
• Water jet cutting
• Cut the profile

Learn more about sheet metal cutting techniques here

2.2. Sheet metal shaping

Forming or bending sheet metal is an important step in sheet metal manufacturing and is completed with the help of machinery such as press brakes, rolling mills, dies and other equipment. Hot rolling and cold rolling create curved or cylindrical shapes from sheet metal.

The most challenging aspect of shaping is knowing how to bend the material to achieve the desired angle or shape. Because sheet metal has a tendency to spring back to its original shape, a trained operator must master the technique of “bending” the sheet metal to allow it to spring back to the correct angle.

Drawing is the least observable sheet metal shaping process, using a lathe to rotate a sheet of metal as it is pressed against a tool. The deformation process, as its official name suggests, looks similar to the manual lathe turning process and it is used to create round sheet metal parts such as cones and cylinders.

Stamping combines cutting and forming, using complex dies to create complex shaped parts with fewer operations.

Learn more about sheet metal forming techniques here

2.3. Punching

Punching is a method of making holes in metal sheets. This technique relies on a hardened steel die and punch to force holes into the metal and collect scrap metal from the hole.

2.4. Weld or join

Welding and joining bring all the metal components together to assemble them into a finished product. All welding methods can be used including stick welding, MIG, TIG or laser. Solderless joining is typically accomplished with rivets or hardware screws.

Learn more about sheet metal joining techniques here

3. Notes during sheet metal manufacturing

Sheet metal manufacturing process is a flexible manufacturing process that can be used to create a wide range of products, from simple racks to complex machinery. CNC machining, laser cutting, plasma cutting, waterjet cutting, and sheet metal bending are just some of the techniques that can be used in sheet metal fabrication.

A common material used in sheet metal manufacturing is mild steel, which has a relatively low melting point and can be easily formed and welded. Other materials, such as cold-rolled steel and sheet metal of varying thickness, can also be used depending on the specific application.

Engineering drawings are an important component of sheet metal fabrication because they provide detailed blueprints for the manufacturing process. This includes specifying the dimensions, tolerances, and materials required for each part of the final product.

Plasma cutting and laser cutting are two commonly used techniques in sheet metal fabrication. Plasma cutting uses a plasma cutter to cut through metal, while laser cutting uses a high-powered laser to cut through metal sheets. Both methods produce precise cuts that can be used to create complex shapes and designs.

Sheet metal bending is another important process in sheet metal manufacturing, allowing flat pieces of sheet metal to be formed into three-dimensional shapes. Roll forming is another method that can be used to create complex shapes by continuously bending and shaping sheet metal.

Injection molding is another manufacturing process that can be used in sheet metal manufacturing to create plastic parts that can integrate with sheet metal components. The process involves melting plastic pellets and injecting them into a mold, then cooling them and removing them from the mold to create the final part.

4. Surface finishing of sheet metal fabrication

• Anodizing thickens the natural oxide layer on the metal, which gives the component excellent corrosion and wear resistance properties. It improves the hardness and durability of the surface with a smooth, matte finish.
• Bead blasting (also known as sandblasting) involves shooting a high-speed jet of sand or other abrasives at the metal sheet, giving it a matte texture and preparing it for coating.
• Powder coating involves spraying powder paint directly onto a metal part, then curing the part in an oven or with ultraviolet light to form a wear-resistant gloss or semi-gloss texture.
• Polishing is when a cloth wheel “polishes” or rubs the metal surface, giving it a shiny appearance.
• Electroplating is often used for decorative purposes but also has anti-corrosion properties. Chrome plating is one of the popular forms, widely used in the automotive industry.

5. Design considerations for sheet metal manufacturing

• Without getting too technical or providing too many details, here are some general considerations when designing sheet metal parts:
• Wall thickness: Since sheet metal parts are made from a sheet of metal, it is essential to maintain a uniform wall thickness across the entire part.
• Remember the kerf: Laser, plasma, and waterjet cutting eliminate a small amount of the material cutting process. This loss of material is called undercut, and designers need to plan for this, especially if parts must fit together when assembled.
• Add fillets: The outside corners of sheet metal parts are sharp, so adding fillets will help prevent cuts when handling the part.
• Specify a hole diameter larger than the plate thickness: Holes with a diameter smaller than the part thickness can result in distortion or inaccuracy due to distortion caused by the laser beam. Stick into a hole with a diameter equal to or greater than the thickness of the sheet.
• Holes spaced at least twice the sheet thickness apart: Holes too close together can lead to deformation or breakage of the part during forming or bending.
• The holes should be at least the thickness of the plate from the edge: If the holes are placed too close to the edge, the hole will be more likely to become deformed, especially if the part undergoes later forming.
• Make sure the holes are at least twice the sheet thickness from the start of the bend radius: If the hole is placed too close to the bend, it may become deformed or may act as an unintended undercut want.

The above list is not exhaustive as there are many factors to consider in any sheet metal fabrication process. Creating a design using best practices, selecting appropriate materials, ensuring steps in the fabrication process are completed correctly, and selecting the best surface finish, if necessary, requires Ask for a lot of planning.

Conclusion

High quality sheet metal manufacturing is the result of much collaboration, skill and experience in a well-run manufacturing environment. From choosing the right metal to choosing the right fabrication and finishing method, every step is critical to achieving the quality of the final product. Understanding the basics presented in this article can be the foundation for anyone delving into the world of metal fabrication, whether you are a seasoned professional or just starting out. Remember that design considerations are important as they play a vital role in the functionality, durability and aesthetics of your finished piece. Armed with this foundational knowledge, you are better equipped to solve complex problems and realize the full potential that sheet metal manufacturing offers.