What part of a welding electrode is the core filler material?

• A. Shielding Gas
• B. Flux
• C. Core Wire
• D. Electrode Coating

Answer: (C)

The core filler material is the core wire—the metal inside the electrode that actually melts and becomes part of the weld. The outer coating, called flux, provides shielding, deoxidizers, and sometimes slag, but it does not serve as the filler metal itself. In many welding types, shielding gas is used in addition or instead of flux, but it’s not the filler material. So, the metal at the center—the core wire—is the filler that fuses with the workpieces.