Compared with the common axial fan, HF- I type axial fan and HF- II multi-blade adjustable axial fan have a larger air volume, a higher pressure and other features, which is widely used for ventilation in the mining factories, civil buildings and etc. In addition, the profile of HF-II is shape with chromium blade and the angle adjustment can be arbitrary. With the optimal design, the hub and the blades are casting from good quality aluminum alloy in precision, which allows high intensity and a certain ability to decay. HF- I / II are suitable for the places that don’t contain flammable, explosive and corrosive gases with the temperature no higher than 80℃.