In ER70S-3 designation, the letter S denotes short circuit transfer.

In ER70S-3 designation, the letter S denotes short circuit transfer.

• A. True
• B. Spray transfer
• C. Solid wire
• D. False

Answer: (D)

In GMAW filler-metal designations, the letters describe the wire type and chemistry, not how the metal transfers. ER70S-3 is a carbon-steel solid wire used for MIG welding of carbon steel, with the S indicating steel/solid wire. The 70 refers to the approximate minimum tensile strength (about 70 ksi), and the dash 3 signals a specific deoxidizer package within that family. The metal-transfer mode (short circuit, spray, etc.) is determined by welding process parameters and shielding gas, not by the designation itself. So claiming that the S denotes short circuit transfer isn’t correct.