Consisting of thin and flat pieces of metal — typically steel or aluminum — sheet metal plays an important role in the construction and manufacturing industries. In the construction industry, it’s used as panels for buildings and houses. In the manufacturing industry, sheet metal is used for automobile components, heavy machinery, floors and more. When making sheet metal, however, companies often use one or more of the following forming processes.
#1) Curling
Curling is a sheet metal forming process that’s used to smooth out the otherwise sharp and rugged edges of sheet metal. Sheet metal often contains sharp edges with “burrs” after it’s initially produced. Curling is a forming process that involves de-burring sheet metal to produce smooth edges.
#2) Bending
Another common sheet metal forming process is bending. Companies typically perform bending on sheet metal using either a brake press or similar machine press. The sheet metal is placed over a die block, at which point a punch presses down onto the sheet metal. Bending doesn’t actually create holes in sheet metal. Rather, it lives up to its namesake by “bending” sheet metal in the shape of the die.
#3) Ironing
Sheet metal may also be ironed to achieve a uniform thickness. Most aluminum cans, for instance, are made of ironed aluminum. In its raw state, the aluminum sheet metal is too thick for beverage cans, so it’s ironed to achieve a thinner, more uniform composition. Ironing involves the use of a punch to force sheet metal between two dies.
#4) Laser Cutting
Laser cutting has become an increasingly common sheet metal forming process in recent years. With laser cutting, sheet metal is exposed to a high-powered laser that burns holes in the metal. It’s a faster and more precise cutting method that can even be performed automatically using a computer numerically controlled (CNC) laser cutting machine.
#5) Hydroforming
A lesser-known sheet metal forming process is hydroforming. Like deep drawing, hydroforming involves stretching the blank over a die. So, what’s the difference between hydroforming and deep drawing? The key difference between these two processes is that deep drawing requires multiple draw reductions, whereas hydroforming is performed in just one step.
#6) Punching
Finally, punching is a sheet metal forming process that involves the use of a punch and die set to create holes in sheet metal. The sheet metal is placed between the punch and die. Next, the punch presses down and through the sheet metal to create a hole.
No tags for this post.
No tags for this post.
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:
-
Sheet metal materials
-
Sheet metal grades
-
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:
-
Sheet metal thickness
-
Flat pieces of metal
-
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:
-
A sheet metal press
-
Press brakes
-
Metal bending
-
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.