... -400amp heavy duty welding machine 1,low price, energy saving. 2,mosfet design 3,Welding thickness:2.0-12.0 ZX7-400amp heavy duty welding machine A. ... for outdoor movable working and high altitude working. 6.Beautiful shape of seam, good quality of arcing starting, stable arc ... make as your specific requirements F.Two stage quality control 1,Machine Adjustment, test the inner components to maintain the ...