Stud welding is a process where a metal clasp is welded to another metal component using an electrical arc to heat the parts. It is one of the many forms of welding that professionals in the manufacturing, construction, and engineering industries can use.
Because of its pace, precision, and the efficient results it produces, many prefer the stud method for welding. Here, we take a detailed look at what stud welding is.
An overview of stud welding
Before we get into the details of things, let quickly take a quick overview of stud welding and what it entails. Stud welding is a comprehensive method of single-step fastening that utilizes clamps called weld studs.
Welded studs exist for a range of applications in several styles, such as tapped, unthreaded, threaded, etc., as well as many shapes and sizes.
For a high-quality, high-resistance lasting bond, a weld stud can be immediately connected to a metalwork plate. The metal at the base and the soldered stud fastener need not be similar materials.
For instance, it is possible to weld together these combinations—copper to steel, brass to steel, brass to copper, and related combinations.
Compared to other methods for fastening, stud welding is cheaper and can be used in areas that do not require other fasteners to be used. Weld studs can be mounted by one man in less than a second, operating on one side of the piece of work.
There are several reasons why the method of welding the stud is preferable to other repair methods. Some of them are discussed later.
What is stud welding?
Now that we have provided a quick introduction and overview of stud welding, it is time to look at ‘what is stud welding’ in a bit more detail. This includes discussion on the reasons to choose stud welding, the stud welding process, and the benefits of stud welding.
Why choose stud welding
There are several advantages of using stud welding when it comes to adding fasteners as opposed to other methods for welding. With fewer steps involved for extremely quick attachments, stud welding needs access just to one side of the parent material.
Additionally, in the majority of applications, it also does not trigger reverse labeling.
This means that stud welds are also extremely powerful because you don’t have to cut and remove burrs from holes, which can also trigger leakage and discoloration problems. The welded joint is generally stronger than the parent material, or the initial stud.
Hence, this method is preferred by many practitioners over other methods such as bolting, drilling, back welding, tapping, and spot welding.
The equipment used in stud welding
When discussing ‘what is stud welding’, an important thing to know is the equipment used in this welding process. The following are the things generally required for performing the stud welding process:
- Cables to bind together the device components and metal at the base
- A power source with direct current
- A welding gun
- A controller
The controller and power source are merged in the majority of systems as one part referred to as the “Welder.”
The stud welding processes
There are three main types of stud welding, often referred to as the stud welding processes. The following are the details pertaining to these stud welding processes.
Capacitor-Discharge (CD) welding
A popular stud welding method, Capacitor-Discharge (CD) welding is used in situations where welding joints have to be nearly perfect and the reverse tagging has to be maintained to a bare minimum for the sake of aesthetics. It is extremely effective on parent materials like aluminum, stainless steel, and mild steel that are tidy and smooth.
CD welding operates with components with a minimum thickness of 0.7 mm, making it the best choice for dense parent material. CD is more stringent with respect to the diameter of the stud which can be welded as opposed to other processes.
Studs with narrower diameters, such as 1 mm, are important for efficient and reliable welding.
Compared to other forms of stud welding, CD welding is not that flexible. Due to this, if your parent material is dusty, powdered, or contorted, Drawn Arc (DA) welding will be the best option.
While CD welding is not as sensitive to defects on parent material as other forms of welding, it is less costly and quick (and therefore it is popular).
CD welding requires capacitors mounted to specific pre-defined voltages based on the diameter of the stud and the density of its kin. The stud is mounted so that it meets the parent materials by the weld pip, a little bit of metal on the CD studs’ base.
As a result, an electric charge emitted via the sheet of metal, and the stud warms up both to its boiling points and produces a melting pool.
The CD equipment required to produce durable stud welds is light, simple to use, and won’t take up a lot of room. When selecting a CD gear, there are many considerations to bear in mind, such as how the weight of the welder, the difficulty in using it, its charging time, its speed of welding, and its versatility.
Different considerations can be more of a concern when selecting CD equipment, based on the activities planned.
Drawn Arc (DA) stud welding
Drawn arc stud welding is the optimal process for parent materials greater than two mm in diameter. The arc form developed matches bigger fasteners in diameter (from three to twenty-five mm).
It offers good infiltrating outcomes with an extremely regulated, tidy weld filet. Additionally, DA deals with materials with imperfections or curves, which makes it a more versatile process than CD.
However, to realize these outcomes, it does need a three-phase, 415-volt source of power. Therefore, CD may still be the most feasible option for certain operations.
The drawn arc method often includes ferrules, which are shields made from ceramic to protect the pool of molten metal between the stud and the parent material. This adds additional phases to the process.
The person operating the weld positions the stud on the plate in a drawn arc and activates a pilot arc, while the stud rises up to a pre-determined height. The central arc below melts the stud’s weld end into a liquid pool on the plate.
The force that returns casts the stud into this bowl. The adjacent ferrule frames the filet; then the ferrule is chipped away by the user.
The DA process is the only form of broad diameter stud-welding and is ideal for multi-gun applications. Because it incinerates and interacts with pollutants, the utilization of flux in the stud often keeps the weld area safe.
Short cycle stud welding
Although it is quite similar to DA, short cycle welding (SC) can perform faster than the latter which is what makes it different. You can weld in ten to a hundred milliseconds to a parent material using this method.
SC welding uses a mixture of the DA and CD processes, and it can be used with heavier and more fragile components than CD but not as dense components and studs as DA can handle. For those with limited budgets, SC welding can be a good option, as the tools and equipment are less costly than the ones utilized for DA.
Just like with DA, the SC method needs a welding time and current to be pre-determined based on the diameter of the stud. Just like in CD, a weld pip is present in the studs mounted on the parent material, resulting in a pilot electric arc.
If the stud is raised to the predetermined height, the main arc melts the metal sheet surface and welds the pip to form a molten tub. Like the other methods, the returning force brings together the sheet and the stud to create strong fastening.
There you have it—the three processes for performing stud welding.
The benefits of stud welding
The following are the main benefits of performing stud welding:
- No special qualifications and no preparation needed to mount
- It is quick. A 3/4 “fastener will require under a second to weld
- It is welded and does not operate independently as a press-in fastener
- It is one-sided. It ensures you don’t need access to the other side of the work item
- It is best in terms of aesthetics. There are no markers for mounting a fastener as a single-sided fastener
- A Complete cross-sectional weld is what a stud weld is. This means that the fastener’s entire face is welded in place and provides a solid, stress-free weld
- It is safe
This list is not exhaustive, and there are many more benefits of stud welding.
Summary
In this article, we discussed the different stud welding processes, the reasons to choose stud welding, and the benefits of using the method. With this information, you can decide whether using stud welding processes for your application is a good idea or not and also which stud welding process you should use for your application.