Solid filler metals are composed of a single metal or alloy, while flux cored filler metals have a hollow center filled with flux. Flux cored filler metals produce a slag that protects the weld from oxidation and contamination, making them ideal for outdoor or windy conditions.

The appropriate filler metal depends on the base metal being welded, the welding process, and the desired weld properties. Consider factors such as the metal thickness, joint design, welding position, and the required strength and corrosion resistance.

Gas-shielded welding using filler metals provides excellent weld quality and control. The inert gas protects the weld pool from contaminants in the atmosphere, resulting in clean and consistent welds with minimal spatter and porosity.

Filler metals should be stored in a cool, dry place away from moisture and contaminants. Keep them in their original packaging or sealed in airtight containers to prevent oxidation and degradation.