Mild Steel Capacitor Discharge Tap Pads or Internal Thread CD Weld Studsare used in all types of applications. Most Capacitor Discharge applications involve thinner gauge material with a ¼” thickness or less. The Capacitor Discharge Stud welding is a process by which a metal fastener is welded to a base metal through a face weld. CD Stud Welding can be used with dissimilar metals such as ...