Sheet metal fan assembly

A sheet metal fan assembly including a sheet metal hub having a plurality of radially extending spider arms each provided with a sheet metal fan blade, the improvement comprising, a radially extending rib on each arm thereof and extending outwardly from the surface of the arm, each blade provided at its radially inner portion with a rib extending radially along the blade and projecting outwardly from the surface of the blade, each blade being rigidly attached to an associated spider arm with the said rib on the blade and the said rib on the spider arm being in registered relationship, each blade being provided with a reinforcing channel intersecting with and branching laterally from either side of the radial outer end of said rib, the channel projecting outwardly from the surface of the blade in the same direction as said rib, said channel presenting a radially inner portion extending generally transverse to the longitudinal axis of the blade and arms at the ends of said inner portion which extend in a direction generally parallel with the longitudinal axis of the blade.