Which filler rod is classified under AWS for steel?

The classification of filler rods under the American Welding Society (AWS) system provides important information regarding their composition and appropriate applications. In this case, ER70S-6 is a filler rod specifically designed for use with steel.

ER70S-6 is a tungsten inert gas (TIG) welding filler metal that contains a higher level of manganese and silicon compared to other filler metals. This composition aids in producing a smoother weld with better wetting and penetration, making it ideal for welding a variety of carbon steels. Its ability to provide excellent mechanical properties and adaptability to different processes makes it a preferred choice for fabrication and repair across various industries that work with steel.

The other options, while useful in their own contexts, are classified for different materials. ER4043 is intended for aluminum welding; ER308L is tailored for stainless steel; and ER5356 is also designed for aluminum applications. Therefore, ER70S-6 stands out as the only filler rod listed that aligns specifically with steel applications. This classification is crucial for ensuring the correct selection of filler material based on the base metal being welded.