Which of the following statements best describes the purpose of the R suffix on E7018-R?

• A. To indicate the electrode coating type
• B. To designate the requirements of absorbed moisture testing
• C. To show the electrode is recycled
• D. To indicate the unit is for experimental use

Answer: (B)

Moisture control for low-hydrogen electrodes. The R suffix on E7018-R signals that this electrode has to meet absorbed moisture testing requirements. For low-hydrogen electrodes like E7018, moisture on the coating can raise hydrogen content in the weld metal, increasing the risk of hydrogen-induced cracking. The R designation tells inspectors and users that there are specified moisture-absorption/drying requirements and that the electrode must pass testing to verify it remains dry enough before use. This is about moisture handling and quality verification, not about coating type, recycling, or experimental use. If the electrode doesn’t meet the absorbed moisture limits, it must be properly dried or otherwise reconditioned per the standard.