To understand how to best design and otherwise work with sheet metal, you have to look at the sheet metal manufacturing process.
In industrial manufacturing, sheet metal is cut and mended into various shapes from thin, flat pieces. A wide selection of finished products require sheet metal -- from military furniture to train exteriors -- so it’s important to understand how us metal fabricators do what we do!
The Sheet Metal Manufacturing Process
1. Sheet Metal Grades and Materials
This section will outline:
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Sheet metal materials
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Sheet metal grades
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Sample grades
Sheet metal materials can include stainless steel or aluminum. These come in various grades, with 304 stainless steel being the most common. Other grades can include 410 and 316 stainless steel (also called marine grade).
With aluminum, the grades look a bit different. Aluminum has grades like 1100-H14 or 3003-H14. Each number will be stronger than the next and may require different types of equipment and machinery to work with them.
2. Sheet Metal Thickness and Types
This section will explore:
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Sheet metal thickness
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Flat pieces of metal
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Coiled strips of metal
Sheet metal thickness is measured in gauge. The higher the gauge number, the thinner the piece of metal. Sheet metal can come in foil, too. It can come in a flat piece or in a coiled strip.
When it’s flat, the sheet metal is run through a roll slitter continuously to achieve this effect. Sheet metal coils can range in gauge from 7-20 gauge, and it’s commonly used with airplanes, in commercial roofing, or in the body of a car that’s being assembled.
(Related: Free sheet metal size charts for aluminum, stainless, galvanized and regular steel)
3. The Forming Process – Bending and Roll Forming
The next section will explore:
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A sheet metal press
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Press brakes
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Metal bending
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Roll forming
In order to work with sheet metal, it has to go through a press. The parts will be formed in the center of two different dies. The first die, the one that’s at the top, is what’s called the punch. Hence, when sheet metal is made, it’s cold.
To form it, it can be bent. When bending is done, a small section of the metal will be bent, and the dies will guide the sheet metal in this process. This is a sample bend.
The machinery works with press brakes -- these can help with guiding longer pieces of metal. By repeatedly bending the metal, it can eventually be transformed into its required shape as rollers help to guide it along and shape it.
For being to take place when the metal is roll formed, the sheet metal section that’s fed into the machinery will work with various rolling stations.
These will use a roller die that’s on top of the sheet metal; another die is on the bottom of the sheet. The rollers can be used at different angles. This will eventually change the shape of the sheet metal. As it passes through the roller die, it will start to bend and transform into your preferred shape.
4. Deep Drawing and Spinning
The next steps will explain:
When a particular shape is required of a section of sheet metal, it has to go through a spinning process. To achieve this, the sheet metal will be turned at high speeds while it is pressed against two stocks. The first is considered a headstock spindle. The other is a tailstock that will support the piece of metal while it’s going through the spinning process. Special tools are required to exert force on the metal. The pressure that’s applied help it achieve its required shape.
If, on the other hand, a deep drawing method is going to be applied, the sheet metal will not be clamped down for spinning. Instead, it will be put into a die in a stage that is referred to as cupping. Force will be applied to the piece of sheet metal by using a pressure pad. This will hold the sheet metal in place for the punch to move into an area and create an impression or blank in the sheet metal cavity.
The sheet metal will be bent and a cupping will form while the pressure pad works simultaneously to ensure there are no wrinkles showing on the unaffected areas of the sheet metal. This is a common process in metal fabrication for industrial enclosures that can help give sheet metal indentations.
Final Thoughts
As you can tell there are various ways to transform sheet metal for basic designs. If you have further questions about what to expect in the sheet metal manufacturing process, it’s best to get them answered before you sign on with a metal fabricator. Some vendors offer free consultations or will at least answer a question or two over the phone.
Sheet metal forming is an essential process used in industries such as automobile construction and manufacturing. It involves shaping flat sheets of metal into three-dimensional objects. This guide explores the beginning to end application process and covers forming techniques, equipment, challenges, and materials involved.
Understanding Sheet Metal
Sheet metal is thin, flat pieces of metal that’s easily formed into different shapes. It’s typically lightweight, durable, and capable of withstanding high temperatures. It also exhibits excellent electrical and thermal conductivity. Common types of sheet metal used in forming processes include aluminum, steel, copper, and brass. Each type has its own advantages and applications. For example, aluminum is lightweight and easy to manipulate, but it’s a weaker metal. Steel, on the other hand, is extremely strong but it’s heavy and harder to move.
Basic Forming Techniques
Bending, stretching, and deep drawing are three commonly used methods of forming sheet metal. Let’s explore this further.
Bending, which is sometimes referred to as “press braking,” involves deforming the sheet metal to create angles or curves. It’s used to create a variety of products including hairpins, paper clips, and automotive parts.
Stretching involves elongating metal to achieve specific shapes and is used in the aerospace, automotive, and construction industries.
Deep drawing creates three-dimensional shapes by pulling the metal into a die cavity. This process is used to manufacture a variety of products including pots and pans, stainless steel sinks, gas tanks, and fire extinguishers.
All of these techniques rely on principles such as plastic deformation, elasticity, and stress distribution to shape the metal in order to create a variety of products.
Tools
Sheet metal forming requires the usage of specific tools like presses that provide the strength needed to change the metal’s shape. Other tools include dies, which are an essential part of the metal stamping machines used to draw, shear, or bend metal, and punches that can slit and shape the metal into the form desired.
Safety Precautions
Tools and equipment need to be properly maintained to prevent accidents and injuries. Safety measures and precautions must also be followed whenever operating any of these sheet metal forming tools. Wearing protective gear such as gloves and safety glasses is crucial whenever using these tools or pieces of equipment.
Process Steps and Material Selection
The first step in sheet metal forming is the design phase where the shape and dimensions of the final product are determined. Next, the materials are selected. It’s important to consider the needed strength, flexibility, and the corrosion resistance of the final product. The cost and availability of the material must also be taken into account.
Once all of the materials have been acquired, it’s time to cut the sheet metal into the required size and shape. Then, it must be thoroughly cleaned. Dirt, grease, and any rust must all be removed to ensure the final product is of the highest quality. The next step is deburring to smooth rough edges and prevent people from injuring themselves while handling the product. Next, the metal is formed and inspected for quality and finished with polishes or paints if needed.
Troubleshooting and Common Challenges
Beginners working with sheet metal may encounter certain challenges along the way, and it’s important to keep their potential at the forefront of your mind. Common issues include wrinkling, tearing, and springback, which is the natural tendency of metal to bounce back to its original shape after forming. To avoid these problems ensure the correct materials are used and make sure to apply the correct amount of pressure to the metal; too much or too little can cause defects. Consulting with experienced professionals or seeking advice online can also be helpful.
Conclusion
Knowing the properties of sheet metal, the basic forming techniques, and selecting the proper tools and materials makes successful sheet metal forming projects possible. Challenges may arise, but seeking expert advice allows you to overcome obstacles and achieve the desired result. If you’re looking for assistance with a sheet metal project get in touch with EDCO Fabrication!