ED511232 - Lincoln 7018AC 4.0mm Low Hydrogen Stick Electrode

Technical Overview: Lincoln 7018AC 4.0mm Electrode

The Lincoln Electric 7018AC is a high-quality, low-hydrogen stick electrode designed to meet AWS E7018 specifications while offering superior performance on Alternating Current (AC) power sources. Standard E7018 electrodes typically require Direct Current Electrode Positive (DCEP) for optimal stability; however, many entry-level and industrial power sources are AC-only or have limited open-circuit voltage. This 4.0mm (approximately 5/32 inch) electrode bridges that gap, providing the mechanical properties of a low-hydrogen rod with the usability required for AC welding.

Technically, the coating of the 7018AC is enriched with iron powder and specific arc stabilizers. This formulation facilitates a smooth metal transfer and prevents the arc from extinguishing during the AC sine wave zero-crossing. It deposits X-ray quality welds with excellent impact toughness, making it suitable for code work where specified. The electrode operates effectively on both AC and DC+ polarity, offering versatility in mixed-equipment environments. It is particularly effective for welding carbon steels with tensile strengths up to 70,000 psi.

Storage and handling should follow standard low-hydrogen protocols. To maintain its low-hydrogen status (H4 or H8 depending on specific batch testing), electrodes should be stored in a holding oven after opening if code-quality low-hydrogen deposits are required. For general maintenance, the moisture-resistant coating provides a reasonable shelf life under normal shop conditions.