Automatic equipments for longitudinal welding of tubes and sheets with different welding process: Tig, Plasma, Laser, Mig-Mag and Submerged Arc. They are equipped with a copper support resisting to wear and tear and heat and with a series of pressing plates in brass alloy that lock the pieces. Pieces with thickness from 0.5 up to 4 mm and lengths which may go from 200 to 3000 mm are joined together thanks to the sturdiness and high precision of the mechanical processing. The AUTOMATIC BSL series is suitable for welding pipes by an automatic process of locking the edges of the piece. An adapting cradle, moved by pneumatic or motorized motion, locks the tube aligning the edges and obtaining a very good repetitiveness in big lots of production.