This process uses a direct-current arc from a capacitor. The weld time in this process is between 1 and 6 milliseconds. Capacitor discharge stud welding with the latest equipment can create a weld without burn through showing on the opposite side of very thin metals. CD stud welding is often used for smaller diameter studs and pins, as well as on non-standard materials and for accuracy. On the other hand, drawn arc stud welding is primarily for structural purposes and larger diameter weld studs. Capacitor discharge weld studs range from 14 gauge to 3/8" diameter. They can come in many different lengths, ranging from 1/4" to 5" and larger. They are usually manufactured from mild or stainless steel, brass, aluminium, and aluminium alloy. The tip on the weld end of the stud serves a twofold purpose:  When the tip disintegrates, it melts and helps solidify the weld to the base material. Portable stud welding machines are available. Welders can also be automated, with controls for arcing and applying pressure. CNC stud welding machines can increase the speed and accuracy of manufacturing and construction work. Stud welding is very versatile; typical applications include automobile bodies, electrical panels, shipbuilding and building construction. Shipbuilding is one of the oldest uses of stud welding and the process revolutionized the shipbuilding industry. All other manufacturing industries can also use stud welding for a variety of purposes, from electrical and mechanical to decorative and consumer products. Among the standards quoted in the list of welding codes, the following apply: