What is the common designation for clean steel ER70S?

The designation ER70S refers to a series of filler metals used in welding, with the “ER” denoting that it is an electrode or rod. The “70” indicates the minimum yield strength of the weld metal in thousands of pounds per square inch (where 70 corresponds to 70,000 psi), and the “S” signifies that it is a solid wire suitable for both gas metal arc welding and flux cored arc welding.

The correct answer, which is ER70S-3, is commonly associated with clean steel. This designation refers to a specific classification of wire that is typically used for welding clean steel, providing good weld integrity and cleanliness. This filler metal is ideal for applications where the steel being welded is free from rust, mill scale, or other contaminants.

Other designations like ER70S-2, ER70S-5, and ER70S-6 refer to wires that are formulated differently based on their specific alloying elements and the types of applications they are suited for, such as the presence of additional deoxidizers or variations in chemical composition that might affect performance in different welding conditions. While each designation serves a purpose, ER70S-3 stands out for its common use with clean steel, making it