A-double-inlet centrifugal wind wheels have 15 specifications from 9 inches to 39 inches. It uses galvanized sheet (stainless steel) and is riveted after punched by automatic punching machine; cold assembly is adopted and there is no welding or rupture; it is balanced by dynamic balancing machine, which ensures enough strength in addition of precision, and fan can perform normally this way. Wind wheels bigger than 20 inches are all connected by rivets; those bigger than 18 inches use strengthening tie bars to ensure strength and stability of the wind wheel as well as to meet the requirement of high-speed running of the fan. It is applicable in tank fan, air-conditioning fan and fan box complementary. Its air flow is as much as 2,000-100,000 m³/h, its total pressure is 1,400 Pa, and the balance quality of the wind wheel is G4.0.