In MIG welding, how is filler wire supplied to the weld pool?

• A. Automatically fed into the weld pool
• B. Manually fed into the weld pool
• C. Never used
• D. From the base metal

Answer: (A)

In MIG welding, the filler metal is supplied automatically through the welding gun by a wire feeder. A spool of filler wire is pushed through the contact tip and fed at a controlled rate while you weld. The arc melts the wire and base metal, depositing the filler into the weld pool to build up the joint. This automatic feed is what allows continuous welding without manually adding filler each time. The base metal provides the workpiece, but the filler wire itself is a separate consumable that is introduced automatically.