A non-copper-coated low-alloy solid wire with 0.5% Mo content designed for welding low-alloy steels with high tensile strength and creep-resistant steels. It is produced with an innovative system which considerably improves wire feeding in the torch liners, thus reducing the need for torch spares. No vibrations at all, very limited spattering, smooth and good-looking weld beads. Suitable for pipelines and pressure vessels with operating temperatures of about 500°C. Also finds applications for the repair of medium strength steel castings. Good impact strength at low temperatures. To be used under the shield of Ar+CO2.