In most cases primary purpose for use of high strength steels is weight reduction with resulting benefits in product lifecycle costs. However, as the operating environments vary, it is important to take consideration to the specific requirements for the product in concern. In this study, high strength steel F40SW (YS 460 MPA, UTS 550 MPa) for use in arctic conditions, e.g., icebreakers, are welded with submerged arc welding (SAW) and resulting welds are analyzed for mechanical and metallurgical properties. Submerged arc welding (SAW) is preferred joining process for thick steel plates in shipbuilding.However, as the mechanical properties of steel are improved, restrictions in heat input are often set thus limiting effective use of SAW, and probably therefore Manual Metal Arc (MMA) welding and manual Gas Metal Arc (GMA) welding are typically the processes mainly referenced in literature when welding steels with higher strength levels are studied. In this study, submerged arc welds on F40SW steel were made with overmatching tubular and solid welding wire at heat input levels above the normally recommended maximum of approximately 2,0 kJ/mm. Resulting welds were tested for mechanical properties with focus on toughness properties at low temperatures.Impact toughness KV 150 / 7,5 at -60°C was above 27J for both tested wires in the weld and at the heat affected zone (HAZ). Tested yield and tensile strength of the joints matched unwelded base material and all of the samples were broken at the base material far from the weld and HAZ area. Also the 180° bending tests for both surface- and rootside were passed without remarks. Based on the findings in this study, no obvious limitations for use of submerged arc welding in joining of arctic grade steel F40SW were observed. This encourages for increased use of SAW as economical and environmentally sound joining process for this kind of steel.