Submerged arc welding (SAW) is extensively used in pipe production. Because of the need for high toughness in a pipeline, it is necessary to develop wires and fluxes for high-efficiency SAW to produce weld metal (WM). Investigations are carried out in real spiral pipe production factory by the multi-wire double seam SAW process using constant welding parameters and the same flux. Two different chemical compositions of API-X65 steel and four different chemical compositions of weld electrodes have been used in this investigation to evaluate the effect of WM chemical composition on the mechanical behaviour of welded X65 steels. Vickers hardness, Charpy V-notch (CVN) impact toughness and tensile strength tests have been conducted. The toughness of the WM is lower than BM and HAZ. The WM toughness improvement depends on the weld electrode that is used and increases with increasing Mn content of the weld electrode used. The weld electrode contains B and Ti micro-alloy elements that can produce high toughness WM. The mechanical properties of WM are changed by using different weld electrodes. This work shows the importance of the selection of weld electrode composition in order to improve the mechanical properties of steel welds.