What is the maximum diameter of SMAW electrode allowed in the 2G position?

The maximum diameter of the Shielded Metal Arc Welding (SMAW) electrode allowed in the 2G position, which is a horizontal position for groove welds, is 3/16". This specification is outlined in the AWS D1.1 Structural Welding Code, which provides guidelines for welding qualifications and practices.

In the 2G position, the use of 3/16" electrodes is appropriate because larger diameters can lead to issues such as increased deposition rates and potential difficulty in controlling the weld pool, since the position can complicate the flow of molten metal. The code establishes limits to ensure weld quality and manage heat input effectively, especially in vertical positions where gravity influences the weld pool.

While smaller diameters, like 1/8", can also be permissible, they may not be suitable for heavier sections where larger diameters would provide the necessary penetration and strength. Hence, 3/16" is the maximum diameter specified for this position, balancing the need for adequate heat input and control over the welding process.