Why is it called CD Stud Welding?

CD stud welding, also known as Capacitor Discharge stud welding, is a process in which a stud is seamlessly welded to a base material via a quick discharge of electrical energy. It replaces the need to drill a hole where you would insert a bolt for an attachment point, saving both time and money. The process gets its name from the capacitors that store energy and generate the electrical arc that melts the parent material and stud.  

CD welders can weld studs as small as #4-40 in diameter and up to as large as ⅜-16 in diameter.  Weldable materials include Mild Steel, 18-8 series Stainless Steel, Aluminum, Brass and Copper.  Aluminum is limited to ¼” maximum diameter.

All CD studs are equipped with an ignition tip. When the energy is discharged from the banks of the low-voltage DC electrostatic capacitors, the tip intentionally vaporizes, creating said arc between the stud and base material. The stud is then plunged into the molten metal, allowing for the seamless weld to be formed. This welding process is completed within four to six milliseconds.

This quick process creates an impenetrable weld, making it ideal for applications requiring precision, speed and a clean welding process. CD stud welding is used in industries such as restaurant equipment, sign-making, electrical panels, insulation and aerospace.

An insulation weld pin being installed via CD stud welding

CD stud welding is not common in structural applications. It is more frequently used to weld smaller-diameter studs to a thinner base material. A major advantage to CD stud welding is the lack of reverse side markings unless you use a material that is too thin relative to the stud diameter (see our base material thickness chart here). This gives your final product a very clean look, especially because you won’t have visible bolt heads, making it perfect for ornamental or customer-facing finished products.

CD stud welders can be plugged into a 110v wall outlet, making it more widely available for those with power constraints, unlike Arc stud welders. The installment of the CD studs also does not require a shielding gas or flux like Arc stud welding does, meaning there is no stud burn-off or ‘after weld’ length. 

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