OP 139 is a semi-basic agglomerated submerged arc welding flux for welding of mild and medium tensile strength steels. Used for single and multi-pass but and fillet welding using single or multi-wire submerged arc-welding systems. OP 139 is aluminate-basic type flux. There is a sligth silicon and manganese pick-up as such the use of welding wires with higher manganese levels is required. The flux can be used for longitudinal and circumferential submerged arc seam welding of line pipe using tandem and multi-wire systems. High toughness even at low temperatures. Can ve used with a range of low alloy wires incluiding OE-S2Mo, OE-SD3Mo and OETiBor 33 for the seam welding of line pipe where low temperature impact toughness properties are required. The flux has a high current capacity and such as is suitable for fillet and butt welding applications especially for welds in heavy section steelworks. The weld bead has smooth and uniform profile, blending at the weld toes even at high welding speeds. The slag detachment is good and in most cases is self-lifting. OP 139 is suitable for use with DC or AC using currents up to app. 1300 a on a single wire. Basicity : 1.5