According to what we have learned from archaeology, tubing and piping have been in use since at least 2000 BC. At that time, the Chinese conveyed water using pipes made from reeds. Later, the Romans used pipes in their water drinking and plumbing systems. Using pipes fed by aqueducts, they were able to supply water throughout their vast empire.
The tube fabrication industry began in earnest during the Industrial Revolution. One of the first tube fabrication methods was patented in 1824 by a British person named James Russell. He applied his method to flat iron strip. To perform the task, workers first would heat the metal and fold and weld it. Then, they’d pass it through a groove and rolling mill. Just one year later, in 1825, another inventor came up with the method upon which modern pipe fabrication is based. This method is known as the butt welding process.
The early twentieth century brought more improvements to the tube fabrication industry. For example, during this time period, manufacturers came up with a process for hot forming tube elbows, which made possible the mass production of bent tube products.
During the latter half of the twentieth century (the 1960s), engineers invented a high frequency induction bending machine. This technology allowed manufacturers to fabricate tubes more quickly, more precisely and more portably. One of the biggest contributions from the latter twentieth century, though, was the introduction of CNC machining. This technology, still used to today, has made it possible for tube fabricators to create products at a high volume, while exceeding previous benchmarks for complexity, wall thinness and tightness of bend radii.
Tubing is fabricated using a multitude of metals such as: copper, bronze, brass, aluminum, carbon steel, stainless steel, titanium and other alloys. Each material presents manufacturers with different usable characteristics, such as hardness, durability, corrosion resistance, etc. Manufacturers make their material choice based on which one matches the needs of the application most closely.
Copper is an element, found in nature in its metallic form. Copper is a common alloy “ingredient.” Alone or alloyed, it offers: ductility, malleability, softness, electrical conductivity and thermal conductivity.
Bronze is a ductile alloy made primarily of copper and tin. Bronze tubing is known mostly for its resistance to seawater corrosion and durability.
Brass is another copper-based alloy. Its other main component is zinc. It has an antimicrobial effect on microorganisms and pathogens. This characteristic is given to it by copper. Also from copper is its high malleability of copper. Because it also has a low melting point, brass is easy to cast.
Aluminum is another naturally occurring element. It is valued for its softness, high ductility, lightness, durability, recyclability, corrosion resistance and oxide resistance.
“Carbon steel” is a term that may either broadly reference any non-stainless steel, or specifically reference steel with a carbon content up to 2.1% by weight. Either way, carbon steel, sometimes called “mild steel,” is known to be strong, hard and durable. Note, however, that the higher the level of carbon, the lower the ductility.
Stainless steel is composed of at least 10.5% chromium by mass. This steel alloy is extremely strong and durable, corrosion resistant and oxidation resistant. It is also resistant to most acids and hypoallergenic.
Titanium is exceptionally strong and lightweight material. A transition metal, it is resistant to corrosion derived from aqua regia, saltwater and chlorine. It also exhibits low levels of thermal and electrical conductivity.
There is no one tube fabrication process. Rather, to create a certain tube product, manufacturers may choose to use any number of process combinations. While we can’t tell you the details of every custom metal fabrication project out there, we can go over the process details in a bit broader of terms, to help you understand the steps that go into it.
1. Sketch design
The first thing manufacturers have to do is create a design. They usually do this with the help of CAD software, which makes it easier to visualize and construct. As they do this, they think about dimensions, shapes and necessary material properties.
2. Choose material
As we said, during design, they think about necessary material properties. Once they know the properties (corrosion resistance, ductility, etc.) that the tube will need to have, they pick a material to match them.
3. Acquire stock metal
Next, they get the material. Most of the time, manufacturing companies have the stock tubes or sheet metal on hand. Sometimes, especially for more specialized materials, they have to order them. As we noted early on, tube fabricators do not usually work with raw materials, but rather with premade stock tubes that they manipulate.
4. Perform fabrication processes
Once they have the tubing they need, manufacturers put it through whatever fabrication processes they see fit. Examples include: tube bending, pipe bending and pipe elbow forming. These processes typically involve feeding the tube into some sort of forming machine, or working them manually with a tool like a mandrel.
Perform secondary services
Secondary services support primary fabrication processes. They include things like: swaging, flaring, machining, and cutting (notching, drilling, piercing, piercing).
In the process of swaging, high pressure is used to create sections of thin wall within the tube. Swaging is critical if a tube must fit within an additional tube to ensure a continuous and reliable flow and adjustment system. Swaged tubing can be found in products such as telescoping tubes in tripods, stands, and adjustable furniture. Because of the meticulous nature of the process, swaging should only be performed by qualified personnel.
The end of the tube may be flared to enable it to connect securely to another tube. Tube flaring is a cold working process that involves attaching a gripping die to the tube, then forcing the flare shape by pushing a mandrel into the end of the tube.
Methods of cutting a tube include drilling, or punching holes, or creating notches. Since notching and hole punching require the utmost precision, a CNC machine is ideal to carry out these processes. In cutting a tube, a blade fully rotates around the tube’s interior or exterior circumference. For precision tube cutting, manufacturers can laser cut the tube.
6. Perform finishing services
Once they performed the necessary forming processes, manufacturers complete the project by applying finishing touches. These include processes like: annealing for strength, sanding, polishing painting, powder coating and plating.
7. Prepare product for assembly or shipment
Design and Customization
When making tube products, manufacturers consider variables including: length, diameter, shape, strength, hardness, density and more. You can have your tubes customized in a wide variety of ways, including by: wall thickness, tolerance, color, coating, bend tube radius and shape. Manufacturers create not only cylindrical tube, but also rectangular tube, square tube and irregularly shaped tube. To learn about a supplier’s custom tube capabilities, check out their webpage or send them a request for information.
Equipment is used extensively by trained engineers in the processes of tube cutting, flaring, swaging, and bending. Each piece of equipment is applied to ensure the fortitude of the tubing and the prevention of material diffusion. Although forming processes may be carried out manually, the process time will be longer and much less precise.
CNC Tube Bender Machine
CNC tube bending machines are a popular choice of equipment for tube bending or pipe bending. They are powered by hydraulics and are capable of forming tubes into coiled and zigzagged shapes.
Rotary benders consist of a pressure die, a clamp die, a mandrel and a wiper die. The pressure die holds onto a straight section of the piece (sometimes called the tangent), while the clamp is used to rotate the piece you’re bending. Next, the mandrel supports the interior profile, so that it won’t collapse during forming. Finally, the wiper die makes contact with the workpiece shortly before it reaches the inside radius tangent point. It wipes the material to keep it from wrinkling.
Mandrels are usually shaped like balls, linked ball bearings, or rods with a rounded tip. Plug mandrels, or straight mandrels, are used on normal bends, while the ball bearing mandrels are used for bends that require more precision.
Variations and Similar Processes
Pipe bending is performed using either manual, automated, or semi-automated equipment. During this process, the machine clamps down a length of tubing (to force it through a die) or feeds it through a roller so it takes on the shape of a simple curve.
Tube bending involves the use of a mandrel or a full CNC bender machine. Tube mending can be performed without a mandrel or bending machine, but doing so produces a tube with interior wrinkles. The distortion of the interior structure can lead to lower flow capacity and weak spots. However, if you have a low-performance or non-aesthetic application, this may be okay. High performance pipes, on the other hand, like decorative handrails or hydraulic piping, require unobstructed and smooth tube bends.
Mandrel bending is a sub process of tube bending. It is commonly used in the industrial and manufacturing industries in the production of exhaust pipes, hydraulic tubes, heat exchangers, and fuel lines for motor vehicles. This process makes tubular components by wrapping heat-curing materials around a circular mandrel (a metal ball or rod), or inserting a mandrel into the tube as it is being bent. Mandrel bending, or mandrel tooling, creates kink and wrinkle-free tube bends.
Rotary bending involves the use of mandrels and different dies to control metal flow during bending. A precision mandrel sits inside a system of dies designed to hold the shape of the tube-product-to-be, and directs metal flow.
Pipe Elbow Fabrication
Pipe elbows, which are often components of hydraulic and flow applications, are formed via a combination of mandrel bending and swaging or flaring. Mandrels and sand are key components in helping a tube to retain its interior shape as it is bent. If the former, a mandrel is placed inside the tube before it is cold bent. If the latter, sand is packed into a pre-bent tube before it is bent again.
Welding is a joining process that brings material together via fusion. Fusion is brought on by heat or heat and pressure.
Tube fabrication is a great choice for many reasons. First, it is incredibly versatile and offers nearly endless design possibilities. Along these same lines, because there are so many different fabrication processes, machinery and material options, there is bound to be something in your budget, no matter what is it.
Things to Consider
When searching for suitable tube fabricating services, you must consider a manufacturer’s production capabilities and the characteristics of the desired tubing. There are certain skills and types of machinery required to manufacture metal tubes, depending on your desired tube’s physical properties and its ultimate function. For this reason, the task of finding a tube fabricator can be quite daunting. To help relieve some of the pressure, we’ve compiled for you a list of several highly skilled tube fabrication service providers who operate with state-of-the-art equipment. To learn more about each of them, take a look at their profiles, which you will find by scrolling up. Keeping in mind your specifications, pick out three or four to whom you’d like to speak directly. Reach out to each of them, and then compare and contrast your respective discussions. From among them, choose the one you believe will best serve your needs.