Weld Pins Capacitor Discharge Studs are designed to be welded to thin gauge sheet material using tip ignition according to the capacitors discharge welding process. Capacitor Discharge Studs are available in many different sizes, from a base diameter of a 2 mm stud up to 12 mm. Standard material for CD Studs are: Low Carbon Copper Flashed Steel, Stainless Steel, Aluminum Alloy, and Brass. Other grades, i.e. AISI 316 (A4), AISI 310 are available on request Studs made of steel 4.8 are protected against corrosion by copper coating. (Thickness : 3 to 5 µm).