Manual folding machine is a kind of equipment used for sheet bending. The upper and lower sheet plates are clamped, and the lower sheet plate is folded to the desired angle. Manual folding machine includes ordinary folding machine and TDF flange folding machine, and its length specification is 1300mm / 1500mm / 2000mm / 2500mm. It is also one of the commonly used equipment in air duct manufacturing and processing. The manual common flanging machine is used for the bending of 0.5-1.5mm flat plate. The manual TDF flanging machine can be used for the bending of air duct because the lower knife is provided with groove.