Drawn arc stud welding, otherwise known as drawn arc or stud welding, is a process that quickly joins base metals to fasteners. This is achieved using a controlled electric arc process to melt the end of the fastener and secure it to the base metal. There are several types of drawn arc welds. Tip ignition, drawn arc, CD (capacitor discharge) with gap fall into the “drawn arc” description. There is also a drawn arc with ceramic which is slightly different adding a ceramic ferrule to the process. Drawn arc welding can be used with steel, stainless steel, and aluminum metals.
How Does It Work?
While drawn arc stud welding seems simple, it actually involves the combination of complex chemical, electrical, and molecular reactions that occur in quick succession. This process can be performed with a hand gun, but in higher volume production requirements a robot or servo system is generally used.
The process follows these steps:
- In an automated system the stud fastener is auto fed into the DC-powered welding head and held under spring tension.
- The gun is positioned on location and the stud is set firmly on the work surface.
- A trigger initiates the cycle energizing the gun solenoid. The stud is slightly lifted from the surface creating an “arc” which then melts the flux loaded end, with the spring tensioner pushing the fastener into the surface and adjacent area.
- The “ceramic” drawn arc has a slightly different process. The ceramic ferrule is added and protects the arc focusing the heat in that area and puddles the metal from the ferrule. The stud in the welding gun then pushes into the molten metal. The ceramic ferrule blocks potential splashing from the molten metal to protect the workpiece. The molten metal, the stud, and the base metal all combine. As the metal starts to cool and harden, it solidifies and turns the three pieces into a single piece of metal. The ceramic is then chipped off or broken revealing the finished weld.
This process results in a cross-sectional weld, which creates a strong, reliable, and long-lasting bond. Not only is the weld strong and resistant to breakage, but it also won’t loosen, weaken, or fail due to vibration. This process creates a more aesthetically pleasing result than conventional welding techniques.
Advantages of Drawn Arc Welding
Drawn arc welding has several advantages over other forms of creating long-term or permanent connections. Some of the most important advantages include:
Drawn arc stud welding creates a high-quality product with an excellent finish. The one-sided weld is incredibly strong and reduces the risk of weak, broken, or loose connections over the lifespan of the item. Because the weld is just on one side of the fastener, it also offers a clean, finished look on the opposite side of the fastener. Product designers can also use the one-sidedness of the weld to create more diverse designs.
This welding process is fast and easy. Each weld takes only a second with the proper welding equipment. Since only one side has to be welded, manufacturers can quickly produce high quality results without delays or complications. The simple welding process can also entirely replace more complex riveting, punching, drilling, and other alternatives to welding. Handled correctly, manufacturers can even paint over welds without additional pre-grinding steps.
Since through-hole preparation is eliminated, the process can be completed in one process, dramatically reducing labor costs. This process also leads to decreased fabrication costs since expensive, oddly-shaped pieces can be duplicated in a cost-effective way by welding multiple studs to a simple stock shape to create a metal fabrication.
Choose Tec-Option for Drawn Arc Welding Solutions
Drawn arc stud welding is quick, efficient, and gives manufacturers an endless array of design possibilities. At Tec-Option, we have over 20 years of experience in providing high quality welding systems to meet your production needs. For more information, or to get started on your automated drawn arc welding solution, contact us today.