What is a defining feature of hot wire GTAW?

• A. It preheats the filler wire so it melts on contact
• B. It uses no filler wire at all
• C. It relies on the electrode to supply all filler metal
• D. It requires the workpiece to be preheated separately

Answer: (A)

Hot wire GTAW is defined by preheating the filler wire before it enters the weld pool, so the wire melts on contact. A dedicated heater warms the filler as it is fed, allowing the arc to deposit metal more efficiently and at a higher rate. The tungsten electrode still provides the arc heat to melt the base metal, but the filler metal is already near its melting point when it reaches the weld zone, which reduces the arc’s direct role in melting filler and improves control of the weld. The other statements don’t capture this distinctive feature: there is filler wire used, the filler metal is not supplied solely by the electrode, and separating preheating of the workpiece isn’t what defines the process.