Details About the weld nut Process

Even though lots of people believe that there is just one basic welding application, there are actually a lot of different applications involved with welding. One of these areas is the weld nut process, where a bolt or formed nut is welded onto another metal piece. This process may contain using weld nut equipment to automatically feed the bolts into the spot welder.

What is weld nut?

Weld nut, or arc stud welding, involves joining the stud to a flat plate by using the weld nut as an electrode. The polarity that is chosen for the particular weld nut application will depend upon the type of metal that is used. For instance, aluminum often requires direct current electrode positive, or DCEP; while steel demands direct current electrode negative, or DCEN.

The weld nuts used in weld nut generally have a flange with some type of small nubs that melt during the process so that you can form the weld. The necked down, un-threaded part of the weld nuts also assist to form the desired weld. Another aspect of this kind of welding application is making use of a flux, called a ferrule. A ferrule is a ceramic ring that concentrates the generated heat, preventing oxidation and retaining the melted metal in the desired weld zone.

One particular type of weld nut process is called capacitor-discharge welding, which is different from traditional weld nut in that it doesn't require flux. The process uses a direct current arc from the capacitor, and welding time is between a mere 1 and 6 milliseconds. Since welding time is shorter in capacitor-discharge welding, the welder can finish the bonding with little oxidation and no actual need for heat concentration.