Sheet metal is one of the most common materials used in metalworking and has been used in one form or another for 1,000 of years. Even though sheet metal is found in everything from industrial kitchens to automobiles to roofs, the sheet metal manufacturing process is fairly consistent across all applications.
It’s generally accepted in metalworking that sheet metal thickness ranges from 0.006 to 0.25. Anything thinner is considered foil, and anything thicker is considered plate. But although the material may be called different names based on thickness, the way each is manufactured is usually the same.
Watching the sheet metal manufacturing process may not be as interesting as, say, a caterpillar's metamorphosis into a butterfly. But it's beneficial to understand each stage from the purchasing/engineering point of view. There are six main stages, each important in creating the ideal finished product.
The Sheet Metal Manufacturing Process
1. Design
The design process is conducted by engineers who work diligently to ensure that the idea put down on paper will result in a product that meets expectations.
Design begins with blueprints, goes on to a rough drawing stage, and ends with finalized drawings. It is extremely important that the design is accurate -- otherwise what is produced may not work in the real world.
A full-service manufacturer may offer to help you with this stage -- after all, who knows better whether a design is manufacturable than the manufacturer itself?
2. Cutting
All sheet metal begins in a sheet form, typically starting with a roll before being cut into sheets. Most designs will require some cutting to remove a portion of the sheet. Cutting is accomplished through applying shearing forces or other processes like abrasion or heat.
The term “shearing” really refers to any of these three processes -- shearing, blanking, and punching. Cuts can also be made without shearing by using laser beams, plasma cutters, or waterjet cutting.
3. Forming
Instead of altering the sheet metal by cutting, forming alters the material by bending it. The goal is to deform the material without causing it to fail, which requires careful analysis of the material.
One common testing method is the cupping test, where a ball is placed on the sheet and pressed into it until the material fails. Once it is determined how much and what type of tension is ideal for the desired form, that tension is applied to shape the metal.
4. Welding
Most sheet metal is manufactured to be a part of a greater whole.
Typically, at least two sheets need to be attached to each other through welding or other techniques. After the sheet metal is cut and/or formed, it is attached to other sheets to create the overall structure of your end product. Welding is the most common way that sheets are attached to one another and any other metal materials. However, it is also possible to attach metal to metal using brazing, adhesives, and riveting.
5. Finishing
There are a number of ways the sheet metal can be finished:
- Paint
- Powder coating
- Silk screening
Finishing your metal components is important for several reasons.
Finishing protects against rust and corrosion. It also gives you a prettier appearance than most bare metals and exposed welds or other attachments. (Though this is irrelevant is your components won’t be visible in the end product.) Finally, finishing removes any unwanted burs or other sharp, potentially hazardous side effects of the manufacturing process.
6. Prototyping
Sheet metal may need to be used in a larger manufacturing process, such as building an automobile. Or it might need to serve a purpose independently.
Whatever the end goal, it’s important to prototype the finished product before moving forward with further manufacturing. That way you can verify that the design is correct and the finished product will actually work.
It’s almost always more cost-effective to prototype before making more of a high-stakes component.
A Partner to the Process
That's it! You now have a beautiful, full-grown sheet metal component.
If you would like more information on sheet metal manufacturing or are interested in learning how to save money in the manufacturing process, we are happy to help. No matter who it is, it’s always nice have an expert opinion backing up your idea!
