Copper or aluminum leads are fastened to the welding machine by means of insulated and uninsulated terminals. What is another name for an uninsulated terminal?

• A. Plug
• B. Splice
• C. Lug
• D. Terminal

Answer: (C)

Uninsulated terminals are called lugs. A lug is a bare metal connector that bolts or clamps directly to a post or stud on the welding machine, providing a solid, low-resistance path for the lead current. Because there’s no insulation, the connection must be properly sized and tightened to the specified torque to maintain a reliable electrical and mechanical bond. When aluminum leads are involved, use an antioxidant compound and hardware compatible with aluminum to prevent corrosion and loosening during service. Other terms like plug or splice refer to different types of connectors, while terminal is a general word—the uninsulated form used here is specifically a lug.