In welding, what type of materials can flux cored wires potentially burn through?

Flux-cored wires are designed for welding thin materials where high heat input is required but also must be managed to avoid burning through. In this context, selecting 20 gauge and thinner steel as the correct answer highlights the effectiveness of flux-cored welding in those scenarios.

20 gauge steel is approximately 0.8 mm thick, and flux-cored wires are suitable for this thickness as they can produce the necessary heat to ensure good penetration and fusion without excessive burn through. If used correctly, flux-cored wires facilitate welding on metals that are relatively thin, ensuring that welds are strong without damaging the surrounding material.

The other materials listed are either too thick or made of materials that do not lend themselves well to welding with flux-cored processes. For instance, 30 gauge steel and materials like aluminum and copper present different challenges. Aluminum and copper have different thermal properties and require specific types of welding wire and techniques. By focusing on 20 gauge and thinner steel, it showcases the versatility of flux-cored wires in common welding situations involving thinner ferrous materials.