Have you ever wondered just how raw metals are formed into the products you see on a daily basis? How does a sheet of metal become a highly-tuned medical instrument or the engine of a car? The metal fabrication process is as varied as the applications it serves, but understanding even the basics helps us appreciate rewards that much more.
What Is Metal Fabrication
To fabricate metal is to build finished products from raw metal materials. Metal fabricators work with things like plate metal, formed and expanded metal, castings, fittings, flat metal, sectional metal, and welding wire and employ processes like cutting, bending, welding, forming, machining, and assembling to create tools and equipment. Metal fabrication is used in every kind of production industry, commercial, industrial, and structural.
What are the Main Steps for Metal Fabrication?
The metal fabrication process has countless applications, and the exact steps reflect them. However, there are some consistencies across the board.
Unsurprisingly, the first step of the metal fabrication process is to design what you want to create. These drawings must reflect the manufacturer’s intended measurements and capabilities. Nowadays, it is most common to create such drawings with computer aided design (CAD) software.
This kind of software allows engineers to finely plan each metric and angle, accounting for the necessary complexities of what the product must be able to do. The 3D models can actually be tested within the software, allowing changes to be made without wasting any metal. When the designs are complete, they often can feed directly into welding machines and other fabrication equipment.
Fabrication is the general term for the forming of raw metal. This usually refers to metal plate, two inches thick or more, and processes such as cutting, folding, assembling, and finishing.
Cutting reduces raw metal to the components ready to be shaped. There are many ways to cut metal, including mechanical shearing, water jet cutting, laser cutting, and plasma cutting. These range in levels of precision and utilize different tools, things like lathes, shears, mills, and nibblers.
On the less precise end of the spectrum, mechanical shearing is great for cutting through very thick sheet metal and force is prioritized. On the other hand, laser and plasma cutting are highly attuned processes and make very precise cuts. If a project has an especially low tolerance for error, these cutting methods are likely the right fit.
Other Reductive Methods
Cutting is not the only way to reduce metal to smaller pieces. The best method depends on what kind of result the fabricator is hoping to achieve:
- Shearing—Metal shearing uses blades installed at various angles to produce diagonal cuts, especially in bronze, brass, aluminum, or stainless steel. The blades create straight cuts but can be used in succession to produce a variety of shapes. Shearing is most commonly used on flat sheet metal.
- Notching—Notching, also called nibbling, is similar to shearing though it allows for greater precision and detail, achieving angles that aren’t possible with standard shearing processes. The notching process usually requires multiple rounds to achieve the desired shape.
- Punching—Punching is used to create holes in rolled or sheet metal. It uses a metal punch situated above the metal and a die placed underneath it, pressing through the metal to produce a metal slug.
- Blanking—Blanking is similar to punching and used to create larger pieces of metal that are more likely to undergo more work. Blanking works best on sheet or strip metal.
Once metal has been cut, it is then formed into the desired shape. Forming may be the heart of the metal fabrication process. When working with metal that is roughly already in the right shape, forming may mean employing many different techniques, including stamping, bending, folding, punching holes, and machining.
On the other hand, sometimes molten metal is poured into a mold and allowed to harden in the right shape. This process is referred to as casting. There are several different types of casting, including die casting which uses a die instead of a mold. Once the metal solidifies, it can be further shaped with drills, punches, or lathes.
The assembling component of the metal fabrication process requires all the necessary pieces to be brought together and joined into one final product. Each piece must be fitted together correctly, usually held in place with clamps, and then permanently joined using a method appropriate to the product (i.e. screwing, riveting, bonding, or welding). Each of these methods has further variations, and the blueprints will determine which is best.
Once the product is formed and joined into a complete unit, the finishing touches are applied. These depend heavily on how the product will be used and the conditions it will face out in the world. It is common for products to be rust-proofed, colored, or glazed, usually with paint or powder coating. Other finishing processes include heat treatments, deburring, plating, polishing, brushing, and shining.
Once fabricators and engineers determine that the finished product meets specifications exactly, other finishing touches like manufacturer-specific decals, logos, and serial numbers can be applied.
Installation of a finished product is sometimes included in the metal fabrication process. This allows the team responsible for fabrication to be on-the-spot to make adjustments and corrections as needed. It can be helpful to have the team familiar with the product (with the correct expertise and equipment) on-hand as installation occurs to avoid any snags in the process.
While maintenance, including necessary repair and routine service, are commonly performed by site-specific technicians, some manufacturers may feel it necessary to offer such services as part of the metal fabrication process.
Looking to the Future of Metal Fabrication
Metal fabrication is an integral part of almost every industry on the planet. It produces the pieces for aircraft or ground vehicles, both commercial and military. It gives us equipment for agricultural work and construction applications. It shapes medical equipment and scientific instrumentation. It is responsible for equipment like fracking tanks and pumps in addition to the components of alternative energy structures. From home appliances to car seats, metal fabrication plays a part.
As a career path, working in metal fabrication is a pretty safe bet. With nearly unlimited applications that show no sign of fizzling out, if you have any interest in shaping metal, you too can be a part of the metal fabrication process.