The presence of -R in E7018-R affects the electrode's requirements related to which of the following?

• A. Absorbed moisture testing
• B. Surface hardness
• C. Machinability
• D. Color of the coating

Answer: (A)

The key idea is that the -R suffix on E7018-R flags a moisture-related requirement for the electrode. Low-hydrogen electrodes rely on controlled moisture content in the coating to keep hydrogen levels in the weld metal low. The -R designation indicates the electrode can be sensitive to absorbed moisture, so there is a specific need to verify how much moisture the electrode has absorbed through absorbed moisture testing. If the moisture level is too high, hydrogen can cause cracking in the weld, so you’d need to dry or recondition the electrode before use or select a different stock. This moisture-focused requirement is why absorbed moisture testing is the relevant concern. The other properties—surface hardness, machinability, or coating color—aren’t dictated by the -R suffix.