Electric lock seaming machine can lock square HVAC air duct. The sheet thickness range is 0.3-1.2 millimeters. This machine is small and very easy to operate. It's suitable for lock closing duct on site due to convenient to move. Lock seam closing machine consist of square duct lock seaming machine and round duct lock seaming machine. The square duct lock seam closing machines consist of hydraulic vertical, pneumatic horizontal and electric hand lock seam closing machine. It's an important component of all HVAC air pipe forming machines, we can operate the electric sheet metal hand lock seam closing machine with other HVAC duct forming machines together to achieve a complete duct processing, for example, metal TDF flange forming machine, TDF sheet metal bending machine, flat metal sheet grooving machine, lock former machine, electric cutting machine, flange clips cutting machine and so on.