AC vs. DC Polarities in Stud Welding

Stud welding is a manufacturing application that is made possible by electricity. Before the development of electrical currents into various systems usable by individual consumers and businesses alike, the only format of welding possible was the ancient technique of forge welding. With the use of electrically generated currents, stud welders can create a bond between the stud and surface material that is stronger than either metals put together. If you are using stud welding on site, Northland Fastening Systems (NFS) can provide anything you might need, including welding studs, welding units for rent or purchase, and welding accessories for both drawn arc and CD stud welding.


When it comes to stud welding, there are two electrical current polarities that can be used depending on the welding situation and tools used: alternating current (AC) and direct current (DC). For the most part, DC polarities are used in almost every stud welding application. However, there are some instances when AC polarities are necessary and advantageous.


DC Polarities in Stud Welding


DC polarities move in what is essentially a straight line. The electrical current, whether positive or negative, flows directly from the power source through the tool and is applied at the weld site in either a capacitor discharge weld or a drawn arc current. DC welding is typically used because it provides a more controlled weld with a smoother arc that is stable and predictable. Positive DC welding performs a higher penetration into surface material for heavy-duty welding studs, while negative DC welding has a lighter penetration but greater deposition for effective welds on thin sheet metal.


AC Polarities in Stud Welding


AC polarities have a balanced transition between positive and negative direct currents throughout the application. Because of this, AC welding is beneficial over DC if you need lower penetration and an overall different type of weld. AC welding is a secondary option if the location of the worksite only offers that type of current, but it is also used in specialized welding processes such as welding magnetized materials. In addition, AC welding is used heavily in ship building, repairs, and other projects that need rapid, easily portable welding tools. However, AC welding often has a great splatter and is a messier weld than DC stud welding.


Learn More from Northland Fastening Systems

If you are using stud welding of any kind on your worksite, Northland Fastening Systems can help you determine whether AC or DC welding is a better option. For more information about polarities  or to find a comprehensive selection of equipment, contact us at (651) 730-7770. You can also request a quote online to get started with our team of expert technicians today.