In the E7018 electrode designation, what does the 18 indicate?

• A. The low-hydrogen, cellulose-arc type.
• B. The electrode diameter.
• C. The welding position.
• D. The coating color.

Answer: (A)

In this electrode classification, the digits after the tensile-strength number describe the coating and hydrogen content. For E7018, the 18 indicates a low-hydrogen, iron-powder coating. This combination gives good ductility and weld integrity for structural work, and it’s designed for all-position welding in many cases.

So the 18 isn’t about the electrode’s diameter, welding position, or coating color, and it isn’t a cellulose-arc type. Cellulose-based coatings are associated with other electrodes (like some 60-series or 40-series) rather than the E7018’s iron-powder, low-hydrogen formulation.