Gantry Auto-welding Machine for H-beam steel. Gantry Auto-welding Machine1) Applicable H-beam: a) Width: 200 - 800mmb) Height: 200 - 1,500mmc) Length: 2,000 - 15,000mm2) Dia. of soldering thread: 3.2 - 5mm3) Table speed: 4,000mm/min4) Welding speed: 250 - 1,200mm/min5) Rail span: 4,000mm