What is the significance of an SMAW stainless electrode when the suffix is -15?

• A. It is lime coated and used with DCRP only
• B. It is acid coated and used with DCRP only
• C. It is lime coated and used with FCAW
• D. It is lime coated and used with GMAW

Answer: (A)

In SMAW stainless electrodes, the suffix encodes how the electrode is meant to be used. The -15 designation means the electrode is lime-coated and intended for direct current reverse polarity only. The lime coating acts as the flux/shielding material, helping to control the weld pool and forming a protective slag while the electrode is used with DC reverse polarity. This combination is chosen to optimize arc stability, deoxidation, and weld quality for stainless steels in SMAW.

The other coatings and process compatibility don’t fit this suffix: acid-coated electrodes and combinations with FCAW or GMAW refer to different electrode chemistries and welding processes altogether, so they aren’t described by the -15 designation.