Assuming you are referring to the SMAW process, some toughness is required, and the root pass will be deposited with the process, an E8010/8011-G classification is recommended; e.g. Lincoln's 70+, 8P+. Should you prefer a low hydrogen electrode for the fill, E8018-C3 is a good choice.
I have effectively qualified and used Lincoln's HYP (E7010-G) electrode where toughness was not a concern. HYP+ does have good toughness at -20F.
