Comparing DC and AC Stud Welding Machines

Within the welding industry, there are a broad range of different operations to achieve metal or polymer fusion. The first forms of welding were developed long ago in the Bronze and Iron Ages. Today, many other formats for welding exist, from thermochemical welding and resistance welding to laser welding and ultrasonic welding. In each of these types of welding, other variations of process and application occur. For example, within the category of stud welding, the primary operations are drawn arc, capacitor discharge (CD), and short cycle welding. Whatever type of stud fastening or composite stud construction you’re working with, you can find the supplies and tools you need at Northland Fastening Systems (NFS). NFS provides a complete range of stud dimensions, welding accessories, technicians’ expertise, and a variety of stud welding machines.

 

Apart from the differences among each of the three primary stud welding operations—drawn arc, CD, and short cycle—there can be changes in the way a tool is calibrated for a job or even in the type of electrical current.

 

Like most other operations using an electrical power source, stud welding machines will either be built to handle direct current (DC) or alternating current (AC), both of which have their advantages and disadvantages. The appropriate current pattern for any welder simply depends on the welding circumstances.

 

DC

DC welding units are lightweight and highly portable, making them ideal for job site operations. Because they can be hooked up to most power sources, they can be installed and removed easily between production environments.

 

Though they are a portable option, DC stud welding machines are less energy efficient, using only about 30% to 50% of a power source. They can also require more maintenance than AC welders because they are moved about often.

 

With a DC welder, any arc blown over 300 amp can be difficult to control. Comparatively, AC welders take no effect from an arc blow. Also, DC welders will have polarity in the arc, whereas AC welders have a neutral arc.

 

AC

AC units source power cyclically from their main power supply. The power fluctuates between negative and positive around 50 times a second. This rapid shift creates an even energy flow that generates heat at the weld site.

 

AC stud welding machines tend to be larger than DC machines. They are not portable because they have to be hooked into a transformer for an accurate power source.

 

However, AC stud welding machines have between 70% to 90% energy efficiency, and they are less costly to run long term than DC tools. They also require less maintenance because they are static. Overall, they are cheaper to establish as a workhorse stud welder.

 

Whether you need the benefits of a portable DC unit or an in-house AC welding unit, NFS has a collection of both for rent or purchase. To learn more about our stud welding machines and other supplies, contact NFS at (651) 730-7770. You can also request a quote online to get started with us today.