Abstract: By means of CAD a high-toughness covered electrode has been developed. The deposited metal of the covered electrode is characterized by its high plasticity and low temperature toughness, low temperatures of brittle point and nil ductility transition, low level of diffusible hydrogen, strong resistance to cracking and good technological properties in welding. It is a quality welding electrode matching the HSLA steel with 686MPa strength level, suitable for welding important constructions.