Metal Fabrication is a vast industry that encompasses many metal fabricating techniques and equipment to produce products made from various metals. This article will give you a general overview of metal fabrication and welding, describing different techniques, materials, and equipment used in the industry.
Why Use Metal Fabrication
Evidence for the manipulation of metals by humans goes back to 8700 BC, with archeological finds of copper jewelry being unearthed in the Middle East. In North America, copper was heated and hammered as far back as 5,000 years ago.
Over the millennia, metalworking improved, with many archaeological scientists and historians pointing towards gold possibly being the first metal used, followed by the use of copper and tin, and eventually leading into the copper, bronze, and iron ages.
In the modern age, we simply could not do the things we do industrially and economically without metal fabrication at the helm. Metal fabrication is used to create machines that produce everyday items like toys, kitchenware, and computers. Metal Fabrication is used to create buildings, ships, and aircraft. It’s also used to aid in the exploration of the solar system, whether it’s a probe flying by Pluto, landing spacecraft on an asteroid to take samples, or placing rovers on Mars to explore the surface.
Metal Fabrication Processes
After metal ore is collected, refined, and smelted into various raw stock products like metal sheets, round, rectangular, or square tubing, round stock, bar stock, or other various forms, it arrives at a custom metal fabrication shop or manufacturer to be used in the creation of a final product.
In most cases cutting the metal stock that arrives is the first step. Cutting the metal to a specific length, width, or shape, can be accomplished using a wide variety of equipment and methods such as sawing, shearing, CNC machines like lathes or mills, by the use of lasers, or even by hand using oxy-fuel or plasma torches.
In many cases bending metal to create parts is necessary, and this can be done after the cutting processes using machines like brake presses, hammering by hand or machine, or tube benders for tube stocks.
Many brake presses also incorporate CNC computing to adjust backstops, allowing for precise bends that take dimensionally important features like drilled holes or steps into consideration.
Assembling is simply put, the joining of pieces, in the case of metal fabrication this is also done in several ways depending on the design and functionality of the finished product.
Welding is one of the most common ways to join metal parts and pieces to create a finished product by adding to and fusing metals together to join parts together permanently.
Other methods can be as simple as bolting the parts together, which will require either drilling the holes in very specific locations by hand or cutting the holes out using a laser or CNC machine if the hole locations need to be incredibly precise, to within less than a thousandth of an inch in some cases.
Stamping is a method that can be used to expedite the process by removing multiple different types of equipment needed in some cases.
Metal stamping is a process that takes flat sheets of steel and uses tooling to convert the sheet of steel into specifically shaped parts. Metal stamping is a complex process and uses various metal forming techniques such as bending, piercing, blanking, and punching, in many cases doing all of it in a single process.
Welding is one of the most important parts of metal fabrication. It is the most common method to permanently fix metal parts to form a functioning or finished product.
The most common types of welding used in the metal fabrication world are MIG and TIG welding.
MIG welding is also known as wire feed welding, and it's commonly used for a wide variety of situations and is common in structural welding for construction along with the majority of metal fabrication needs.
TIG welding is different from MIG in the fact that there is no wire feed, instead, the fabricator uses an electrode in one hand and a filler metal rod in the other hand. This type of welding is preferred for welding thin materials, for precision work, and for welding materials like stainless and aluminum.
There are many different types of metal used, but Iron alloys such as the various types of steel are by far the most commonly used alongside aluminum metals.
Other types of metals can include platinum, copper, brass, bronze, silver, gold, and magnesium.
With metal like steel and aluminum being the most common, let’s take a deeper look at the most popular metal alloy types and why different types are suited for different applications.
Mild steel is incredibly common and is a carbon steel that features lower amounts of carbon than other types. Mild steel is not an alloy like other types, thus does not feature other alloying elements. This gives mild steel several properties that make it distinct from other higher carbon or alloy steels, these properties are:
- Better machinability
- Highly ductile
- Better weldability compared to other steels
But having these properties also means that it has some shortcomings such as:
- Nearly impossible to strengthen or harden by heating and quenching
- Less tensile strength compared to alloys
- High amounts of ferrite and iron, making it magnetic
- High levels of oxidation (rust) if not properly coated with paint or other materials
Although having some shortcomings, Mild steel is one of the most popular types used due to its affordability along with being easy to weld and highly machinable.
Stainless steel is highly corrosion-resistant compared to other steel alloys or carbon steel. The corrosion resistance of stainless steel is due to its alloying ingredients which consist of nickel, molybdenum, and chromium, with the alloy amounts varying from 15 to 30%.
Stainless steel is required for a number of products in industries such as the food production and handling industry. It is also necessary for medical equipment and tools, hardware, appliances, and in certain structural or architectural applications.
Aluminum has some great properties that make it valuable and common in the metal fabrication industries. Some of the attributes of aluminum are:
- One third the weight of steel
- Aluminum is incredibly corrosion resistant
- It’s very easy to machine and fabricate
- Has moderate strength despite its low density
Like any material, aluminum also has drawbacks.
- Requires special welding processes
- Dents and scratches easily.
- Can warp, deform, and bend easily, especially when exposed to high heat
- Expensive when compared to steel
Aluminum is used extensively in the aerospace industry in the creation of aircraft due to being lightweight and being fairly strong. Aluminum is also used extensively in the transportation industries for packaging, construction, electrical industries, and more.
There are 7 different common aluminum alloys used for a wide variety of applications, and some alloy variants are better suited than others for certain designs and applications.
Machining can be considered a part of metal fabrication, but in many cases, it can also be considered its own industry. While many metal fabrication companies do both fabricating and machining, there are also companies that focus solely on machining alone.
Whereas metal fabrication can be characterized as building a finished product by adding parts together, machining is characterized by cutting or milling “removing materials” from a piece of metal stock to create a desired shape and part, which is then added to fabricated parts or products.
The machining process is referred to as “subtractive manufacturing,” Whereas Fabrication is typically an additive manufacturing process.
Some examples of machined products and parts are screws, gears, fittings, cogs, crankshafts, fly fishing reels, and vehicle rims.
Custom Fabrication and Mass Production
Many companies in the metal fabrication industry do custom work for customers. These custom jobs are typically short production or the one-time creation of a part or other piece of equipment.
Some examples of the work done by a custom fabrication company could range from custom hand railing for a specific staircase to water gates for a hydroelectric dam or the metal components or beams for a railway bridge.
Mass production metal fabrication focuses on the replication of the same product continuously with an emphasis on maintaining quality while producing as cheaply and efficiently as possible.
Metal fabrication in a mass-production setting can create a wide variety of products such as tableware, firearms, aircraft, and farming equipment.
The modern world we live in today would not be possible without metal fabrication, but metal fabrication did not start overnight. It is a refined process that has been changing over the course of thousands of years. Due to the widespread use of metal fabrication in the modern age, it’s safe to say it will not be going away any time soon.