Common Sheet Metal Fabrication Techniques

NAMF, Sheet Metal Fabrication
September 24, 2021

Sheet Metal Fabrication Is The Backbone Of Our Most Important Industries

The defense and aerospace industries would not be able to exist without it.

Sheet metal fabrication is a detailed and multifaceted process. Bending, shaping, and manipulating tons of metal is no easy task. It involves multiple steps and processes to produce reliable, high-quality products. Fortunately, our sheet metal fabricators are well versed in a wide range of processes and techniques. At New Age Metal Fabricating, we employ these techniques to create durable and reliable world-class products. Now, we want to share those techniques with you. 

In this guide, we’ll go over common sheet metal fabrication techniques and what they are designed to achieve. By the end, you’ll have a better understanding of popular industry techniques and their application. 

What Is Sheet Metal Fabrication?

Sheet metal fabrication is the process of creating customized metal products. Fabricators design these products for use in various sectors across the market. This process relies on various sheet metal fabrication techniques. It may include bending and shaping metal into a specific design. It may also involve cutting the metal into precise shapes. There are many different techniques used for sheet metal cutting including laser cutting, plasma cutting, water jetting, and punching. 

Sheet metal may also go through shrinking and stretching processes until it is the exact size that manufacturers need it to be. Once the product is ready, it goes through a finishing process. Fabricators use various finishes to make the metal more functional and durable. Now, let’s break down each of these metal fabrication techniques. 

Cutting

Cutting is the beginning of almost every sheet metal fabrication process. As the name suggests, cutting involves cutting down the sheet metal to shape it or remove unwanted sections. There are many different methods of cutting, each with its own benefits and drawbacks. 

Machine Cutting

Laser cutting is one popular method. In this method, a laser beam cuts the metal into its desired shapes. Laser cutting removes unwanted material and creates extremely clean, precise cuts. 

Plasma cutting is a similar process. With plasma cutting, a torch directs high-voltage electricity and gas onto the metal, which cuts off unwanted material. This method works on conductive metals like stainless steel, aluminum, and titanium. 

Water jet cutting is another way to design and shape sheet metal. In this method, a CNC machine fires an extremely high-powered jet of water onto the metal to cut it. The pressurized water is typically mixed with an abrasive material to assist with the cutting process. 

Punching is another cutting process. With punching, the metal is laid out over a die that has a cutout in the desired shape. A machine applies a massive shearing force to the metal to punch it down into the intended shape and remove unwanted material. 

All of these methods are typically controlled by a CNC machine. CNC machines use sheet metal fabrication software to cut and move material as programed. They deliver extremely precise and exact results. 

Hand Cutting

There are also several hand-cutting methods. Shearing is one method that uses two offset blades. Fabricators bring the top blade down onto the surface of the sheet metal, which pushes it down on the bottom blade. The process is not dissimilar to cutting paper with scissors. 

Sawing is another method. In this one, fabricators use circular saws or band saws to cut metal sheets, similar to how you might cut wood with them. This process is used primarily for metal that is too thick to cut by other methods. Cuts are often refined with other, finer tools after they are made.  

Bending

Bending the sheet metal is typically the next step in the fabrication process after cutting. The metal is bent into the desired shape by one of two methods. 

The first is form bending. In this approach, fabricators bend the metal manually with hammers and shaping dollys. They bend the sheet metal over an edge or mold and hammer it into the desired shape. 

Using a metal brake is another method that delivers clean and precise bends. In this process, fabricators clamp one end of the sheet metal in place. They place the other end inside a gate. 

The gate lifts the portion of metal inside it, while the clamped side stays in place. This creates the desired bends in the metal. This piece of sheet metal fabrication technology is much more exact than form bending and is more suitable for use on large projects. 

Shrinking

Shrinking sheet metal reduces it down to its desired size. This process is also achieved through several different methods. 

One simple technique is referred to as tucking. In this method, a fabricator forces the metal together between a crevice or folds it over at the edges. Then, they pound the metal down so that it maintains its smaller size. 

Some fabricators elect to use a shrinker. The textured jaws of a shrinker grip the sheet metal from the top and bottom. They pull the lever and the sheet metal is tightly forced together. This method is more precise than tucking. It can be applied to particular areas of the metal and provides a more exact shrinking method. 

Heat shrinking is another option. In this method, one heats an area of metal with a blowtorch or other device until it’s red hot. As the metal cools, it shrinks. This method can be applied to entire sheets of metal. You can also apply a shrinking disc to an angle grinder. These discs use friction to generate heat as they rotate. 

Stretching

Stretching is the opposite of shrinking. It is the process of stretching sheet metal out until it reaches the desired shape and thickness. 

The simplest way to stretch sheet metal is by using a hammer and dolly. Fabricators place an object behind the metal and hit the other side with a hammer. This forces the metal to compress and stretch out around the object. 

Fabricators can also use a stretcher to achieve the desired result. This machine is similar to a shrinker. You place the sheet metal between two flat-textured jaws and the machine slowly pulls it apart. 

Another tool that stretches out metal is the English wheel. This technique uses wheels that roll back and forth over flat metal to compress it and stretch it out. 

Blanking

Blanking is another steel fabrication process. In this technique, fabricators create a flat, geometric shape or blank.

They feed a coil of sheet metal into a large press and die. A machine applies a massive sheering force to punch the blank out of the metal. 

Blanking is a process that is fundamentally similar to punching. The key difference is that punching removes unwanted material and leaves the metal sheet. With blanking, the pieces that are removed are the desired product. 

Steel blanking is an economical process that allows you to produce more with less. The pieces that result from this process are customized to fit specific needs.

It also reduces waste by nesting parts as closely together as they can be. This leaves as little metal behind on the scrap sheet as possible. 

Stamping

Stamping is another process that is similar to blanking and punching. 

Fabricators feed sheet metal into a press where a stamping tool presses it into its desired shape. The stamp, or die, is pressed through the metal with enormous force.

This force pushes the metal down into a mold. The combination of the mold and the die gives the metal its intended shape. 

The difference between stamping and blanking is the specificity of the metal mold. With stamping, the sheet metal is pressed directly into its final shape. Blanking on the other hand creates small, flat blanks that often go through further shaping before they are complete. 

Welding 

Welding is the process of fastening different pieces of metal together. After sheet metal has gone through all its required cutting and shaping, it often needs to be welded to other components to create the final product. 

There are a few different welding methods that are considered industry standards. MIG welding is the most commonly used method.

A filler wire typically made of copper is fed through the tip of a MIG gun. The wire conducts high-voltage electricity that heats the metal up quickly and melts the two pieces together. To protect the weld joint from contamination, the MIG gun also emits a shielding gas. 

TIG welding is another popular method. With TIG welding, welders use a torch that contains a non-consumable electrode. This electrode creates a small and precise electric arc that melts the base metal. Welders add filler rods to the pool of molten metal to join the parts together. 

Oxy-acetylene welding is another, older method. Tanks of oxygen and acetylene create a controlled flame at the end of a torch. This is typically what people picture when they think of welding. 

Welders use this controlled flame to heat the two pieces of metal. During heating, welders add a filler rod that joins the two pieces together. 

Oxy-acetylene welds are often smoothed out with hammers and dollys. This allows the weld joint to lie as flat as possible. 

Finishing

The final phase in the sheet metal fabrication process is adding finishing to the metal. There are many different finishes to choose from, each with its own benefits and disadvantages.  

One popular sheet metal finish is metal plating. Fabricators achieve this process with a machine that uses a chemical bath with an electric current and cathode to alter the surface of the sheet metal.

This creates an outer coating of copper, nickel, chromium, or other metal. This outer coating inhibits corrosion, adds durability, and enhances the final product’s appearance. 

Buff polishing is another technique that adds a smooth finish to the final product. Fabricators create this finish using a machine with a cloth wheel to buff and polish the metal’s surface. This technique is most commonly used for products that need to be smooth or lustrous. 

Powder coating is another popular finishing process. Powder coating involves melting dry plastic powder onto the metal surface. This produces a glossy or textured look. 

Powder coating produces an extremely durable metal. It is most often used when creating parts for high-powered machinery or military application. 

Where powder coating gives metal a glossy texture, sandblasting produces a matte one. With sandblasting, fabricators used a specialized machine that forces sand or other abrasives into the sheet metal at high speed. 

This process sands the metal down and creates a very smooth texture. This is ideal for machine parts that need to slide against each other without catching. 

Trust New Age Companies for All Your Metal Fabrication Needs

The techniques that we’ve covered in this article are the most popular sheet metal fabrication methods in the industry today. But this is far from an exhaustive list. Companies like New Age Metal Fabricating are always innovating and creating new techniques to improve their products. 

It’s no secret as to why we are one of the leading full-service metal fabricators in the aerospace and defense industries. Our founding principles drive us to manufacture to only the highest standards. 

We are a build-to-print manufacturer, which means that we employ the most advanced and cutting-edge manufacturing techniques to meet our clients’ unique needs. 

If you want your engineering and design dreams turned into a reality, contact us today. We provide our customers with complete metal fabrication solutions and only the best quality experience. 

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