Agglomerated semi-basic flux for welding carbon and low alloy steel in single or multipass technique and with single or multi-wire applications. Suitable for use in production of pressure vessel, pipe, boiler, tank, LPG bottles, steel construction and in shipbuilding. The weld metal, produced in combination with corresponding wire electrodes, offers good mechanical properties also at low temperatures. Good slag removal in fillet and groove welds. Possible to use both in alternative and direct currents.