Line Ⅴ combines a feeding metal frame, leveler grooving roll, hydraulic notch and punch square machine, hydraulic shear, movable pittsburgh lock machine, duplex trans-verse flange manufacturing machine, TDF hydraulic folder and CNC system. Is efficient, saves work area by inline positioning of machines. It is possible to produce square duct of small cross section area of 300?00mm. THE WORK THEORY coiler-metal feed-leveler grooving roll＜ shear--cooperate with pittsburgh lock machine or plasma cutting machine. punch shear-form pittsburgh with pittsburgh lock machine-fold with TDF folder to produce?#1055; ?#65292;?#9633; ?#65292;?#8735; ? shear,fold-seal with sealing machine to form TDC